First time shoplifting, please help...?

I stole 80 dollors worth of merchandise from Sears Holding Inc. ( a couple of shirts $14 each, and cologne which was on sale for $25 but the charged my full price.) the tags wernt ripped off and nothing was damaged. the twoo emplyees walked my to the back room and made me fill out paper work they forced me to sign my name on this letter saying im guilty of stealing their stuff. i was trying to read everything on the letter before signing but he rushed me and said they will sue me if i dont sign. the cop came i got aressted, spent the night in jail. it has been 2 months since the incident. i have gone to cout and got a pre-trial diversion. but then i get a letter in the mail from "NEAL C. TENEN" a Sears lawyer say i MUST pay $250 or they will take legal action against me. i ignored the first two letters because i dont understand why i need to pay $250, when the merchandise i stole was $80 (according to them) and they kept the merchandise it was untainted an still in good condition. do i just keep ignoring the letters? willl they sue me, and ruin my pre-trail diversion?