A.R.A. Jean Gray Old Debt Creditor Villa Park, Illinois

I have recently been contacted by a Jean Gray from A R A, stating she was calling to collect on a past due account. The vehicle in question was a vehicle that was awared to my ex-spouse, but awarded to him in our divorce in 2004. The vehicle was repoed in May 2004 (2months after the divorce). He owed $23k at the time. The vehicle was listed as a chargeoff in August 2005. A R A is now contacting myself to seek payment. I have sent them a certified letter, included documents pertaining to ex-spouse, advised them to contact him & discontinue contacting me. I also made them aware the statues of limitations for a written contract in the state of Texas, also mentioned the FDCPA, since they basically advised me of garnishing a bank account, or whatever is necessary to seek payment. Since this I have receive a letter addressed to my ex who does not live at my address ( they told me before they knew how to contact him) and I have received another message to return a call to this Jean Gray. Any advise on additional steps to take is appreciated.