My former Employer is Lying to unemployment possible forgery as well help?

I had been fired from a job I worked at for 8 months, I had never been written up never warned or anything no disiplinary action.Infact i was constantly promoted I was a server/bartender/shiftleader in a restaurant that was taken over by corporate..when the claims specialist called me he said that my old boss said i was fired over two write ups, that never even occured one on the 17th of july and one on the 29th of july, mind you my last day of work was july 25th so right there is obviously a lie...(there was many more lies they told but that does not need to be discussed) anyways the claims specialist believes me hes making them send him the write ups to see if I had signed a write up then I told him they might have tried to forge my signature since they already lied about pretty much everything...and he said i should send him my signature to compare....IF INFACT THEY FORGED MY SIGNATURE WHAT CAN I DO TO RETALIATE?? I was one of their best employees and I was very wrongly fired. and because they cant tell the truth its delaying my unemployment ruining my credit.