I-407 was filed with USCIS on my behalf by forging my signature. How & What steps do I need to take to reopen case with USCIS?

I'm in a crisis situation and I appreciate any advice. I just got divorced and I had received a green card through my ex- husband few years back. My ex-husband hid that I had received green card. I found out about that after I hired an attorney for divorce. When I tried to get the green card from my husband he denied that he had it. I then filed a FOIA request and saw the I-485 approval papers. I then filed for a replacement green card, for which I also had to go through biometrics. After 6 months, I received a letter today saying that the replacement request is denied since “I” had submitted a PR status abandonment request and it was approved last year. The submission date of that abandonment is when the divorce case was in the court. USCIS has asked me to file a motion within a month.