You are out of a job, Nellie. Let it go. I had cancer. I am quite a bit older than you. It's not necessarily a death sentence. Every day you live is important. You have lost a job that is part time, it's gone. You probably have spent a whole lot of mental energy and excess thought process dealing with your firing. But the thing is, so what? They could've fired you no matter WHO made that complaint. They could've fired you because you are old, or because you have cancer. But seriously, so what if you get to sue this person? Who may or may not even exist? So what? Yeah, you want them dead, in hell with their back broke, but really, they're probably like you, not having a whole lot of assets. they're what they call "judgment proof."
You sue them, you get them in small claims court, you show that they "got you fired." Which of course is VERY likely NOT to happen. So what????? They don't have anything you can get. Its' just some small spiteful person who wanted to get you fired because you got on their nerves. Your employer DID NOT have to fire you based in this person's testimony. They wanted to. They choose to. Regardless of who submits what, they could if they wanted to fire you any time for any reason. They have picked this one.
It's over. You need to see about having a good life the rest of your life, not beating this crap to death about what they have done to you or who has done it or what you want to happen or what you want to show.
You are a smart person, you are a bright, encouraging personality. But for heaven's sake (literally!) do not let this particular demon beat you to death. we've talked about my mother, remember back on those other posts? Okay, she lost a lawsuit in her later years. And no matter how sick she was, how bad it got, she always had that to fall back on. Those @#$$%'s cheated me! I was wronged. It made her later years a mess and miserable for her. If you want to be miserable, hate somebody. Seek revenge. They're out dancing.