County Prosecutor and city detective overstepping bounds?

What is the name of your state? Ohio
Greetings...Hoping someone can help here. It's a bit complicated, but I'll try to keep it brief. I'm involved in a situation with another party, where they received a civil judgment regarding a debt (on my part, in absentia). I don't dispute the debt. To make a long story short, after the civil judgment, we made a preliminary agreement regarding payment. This was discussed with a city detective, who encouraged this. We were both subpoenaed to appear before a grand jury on May 1 - served with pretty much blank subpoenas - no defendant or other party listed, nor the reason. In any event, the other party and myself met again on April 30, at which time I handed the other party a written agreement. Since it seemed we still had to show up in court, the other party said they would sign after we talked to the county prosecutor. When I arrived there, I was talked to by the county prosecutor and the detective mentioned before. They said the other party did NOT agree to the terms we discussed, and I had to pay the full amount of the civil judgment. I tried to point at that first, the amount was in dispute, but we (the other party and myself) had already discussed this and had made an agreement, which they disputed. I was then told by the prosecutor and detective that I should NOT speak to the other party, and I had until 11:59 PM on June 4 to pay the entire amount of the civil judgment or face the grand jury. When leaving the room, the other party approached me and said hello. I asked why they lied to me even the night before, and they looked confused. I found out later in the day that the detective and prosecutor had NOT previously talked to this person - they lied. They then went on to tell this other person that they should NOT accept an agreement that we both made in front of witnesses, and told the other party that we should not contact each other. Being the "criminal" that I am, I spoke to the other party later in the day, at which point they said that they were also blind-sided by this county prosecutor and city detective. The other party STILL wants to abide by our agreement, but we're both at a loss as to how to proceed. As neither of us have a restraining order against the other, and feel no animosity to each other, we fail to see how we can be ordered to NOT talk to each other, or how these people can tell either of us what to agree or NOT agree to. The detective in question is the one who told the other party to NOT accept the agreement we made, and said I could "not be trusted". I have NO criminal record, and, in fact, am a rather active member in my community. We're both at a loss as to how to proceed here. I have already contacted the state attorney general, and am waiting for a response. Both the other party involved and myself want to resolve this amicably, but the detective and county prosecutor seem hell-bent on stopping us. This makes no sense. Why pursue this and bring it before a grand jury if we want to settle this on our OWN terms? Any advice would be GREATLY appreciated. Thanks in advance.

Take off the bold print, use paragraphs and then maybe someone will read this.

What is the potential charge ? Fraud ? Forgery ?

You are involved in some criminal activity to attract their attention, yet you have written a post that refers to a civil debt. You are leaving a lot of info out.

Your guess is as good as mine

That's the point - I haven't been charged with anything - at least not formally. The other party already received a civil judgment. The county prosecutor is now running this as a criminal case. But as explained, I only received a fairly blank subpoena - no names mentioned for either party, only a document ordering the sheriff to serve me with it, and it said I needed to be in court at the specified date and time "as a witness for the state".
I have received no restraining order regarding this. Last night, another party who was involved in this contacted me and said that the other person involved in this wanted me to contact them. They stated that they were as blind-sided over what happened on Monday as I was, and still were willing to go through with what we had agreed to, and asked me to contact them if I could find out how we could go about that.
Then, Tuesday morning, I received a message on my voice mail from this detective, saying he spoke to this other person, who he claims said I called to discuss this with and "harassed" them, then went on to say that he and the prosecutor told me not to contact this person, and if I did this again, he would have me arrested for "witness tampering". If this makes little sense to you, don't feel bad - it makes NO sense to me. As I said, I have been served with no papers, no restraining order, only verbal dictates from this detective and county prosecutor.
In the message this detective left on my cell phone, he stated that he was recording what he was saying in that message, so I could not later said I never heard this. I don't know how legal that is, and how he feels it could hold up as anything in court. First off, how would anyone know exactly WHO he called or what time or day he did it? And if this is something official, why haven't I been served any official notice from any court?
I don't know why this is going on. I have never in my life been charged with anything as sinister as jay-walking. Everything that I know regarding this has been what I've been TOLD. The only document I have is that fairly blank subpoena I was served with, asking me to show up as a witness for the state - nothing else.
When I was in the room with the city detective and county prosecutor on Monday, the only thing they said was I have two choices - to go in front of the grand jury or not. They wanted to hear nothing about the agreement the other party and myself had discussed. When talking to this person on the phone Monday night, trying to decipher what had happened, they stated to me that the detective told them they should not agree to anything, and that I "could not be trusted". Again I would mention that I have NO criminal record, and have a fairly good standing in my community, as does my wife. I'm certain that this detective has never heard my name before this incident, and a background check would tell him and anyone else that was interested that I have no kind of record (in fact, I have letters of thanks and so forth from folks in this and other communities for charitable efforts, as well as letters of thanks from prominent politicians for my efforts in political campaigns - including the campaign that helped put this particular prosecutor in office!)
So I'm at a loss. I did send a rather lengthy email to the state attorney general's office, but being an election day, did not receive (or expect to) a reply yet. I also contacted a friend who happens to be a state representative to see what he could advise regarding this, and his office called me back and said he would contact me, but again, being an election day, I haven't heard anything yet.
I have also posted to this and other sites, hoping someone might have some useful insight.