Rubin and rothman

back in July my ex-wife received a summons to court for a debt that she had cosigned with me when we were still married. She immediately called the attorney's office listed on the summons. She told them that I was responsible for the debt as per the divorce. They told her that that didn't matter and that they had not been able to contact me so they were going after her. she called me in a panic and I told her that I would resolve it. Neither of us could afford an attorney at the time so we figured that the best way to handle this was to make arrangements with the lender. the original debt was $15,000 and with "fees and interest" it totaled $24000 per the the collector. I asked if we could have the amount reduced to which I was told to write a letter and they would contact the original lender to see if they would accept. I did that. Time passed and the court date was looming so I contacted the Law office and was told that they had not heard from the lender but they had the date moved. The clock started running again. The court date got closer and I had not heard from the law office. I called them. Still no answer from the lender. Finally two days before the court date we got an answer, the lender refused the offer. We were told we had to pay the total in payments or go to court. Fearing court we decided to take their offer. We signed "stipulation agreements" She had one for $200/m and I had one for $300/m. We faxed the agreements back. We were never comfortable with the agreement but we were being pressured by the "agent" . A week has gone by and I have become uneasy about this. Something told me to look into it. I was lead to the website and see that this law firm has had some problems in the past. I see that they have a history of questionable if not illegal tactic. We never thought to ask for validation because we were being pressured by the clock (court) as well as the agent. In hindsight I feel we should have gone to court and maybe we would have had a more reasonable settlement.
What are our options at this point? We have not mad any payments yet...