breach of contract

I was hired by a consulting firm on 2006 and I had signed an agreement paper with them. Among various other things it says I have to pay the amount the company spends on visa processing and other administrative processing such as training. The company separately asked money on the amount of $1800 which I paid but I have no written documentation to prove.

I had to breach the contract and here is the reason. The company agreed to pay me 30% of the amount I earn from the consulting job. I was working on company A as a part of consulting and company A paid my company $50 per hour but my company lied me and just gave me 30% of $45 dollar.

After two year today I got a certified mail from a Law firm to pay the company according to agreement or else face the consequence of lawsuit.

What will be my option, shall I face the lawsuit and try to explain my situation or pay them what they have asked for which is $7500
I will appreciate your any help.

You need to talk to your own lawyer. If you paid them, why are they now asking for more money?

they are asking for more money beacuse in the contract it says more than 1800. When I signed they said it is just the formality and force me to sign the contract now they are asking for more money.

You need to see a lawyer and show him/her whatever document you signed.

US Law Only!