collections on rental instrument

[danrmn]

What is the name of your state? ks
I rented a musical instrument for my daughter to play at school in sept of 2000. In May 2002, my daughter quit playing the instrument, so I returned it. Today I get a letter in the mail saying I owe $726 in late rental fees and need to return the instrument because the store is cancelliIng my rental agreement because I broke the contract. I called the owner of the store as the letter directed me to do and explained to him that I returned the instrument after the 2001-2002 school year. The owner said my last pymt was in April of 02 and that I didnt return the instrument. I explained to owner that I would need to consult my atty about this. The owner tod me that if he received communication from my attorney he would guarantee a suit as well as criminal charges for theft would be filed against me. The owner said if we could work it out ourselves he would give me a fair deal. I declined as I told him I had been fair in returning instrument. The owner said if I had purchased instrument in april of 2002 when he recvd my last pymt, I would have only owed $192. I don't know what to do now, should I contact owner again or get any attorney. I have no paperwork on this from 4 years ago. I did file chapter 13 bkrptcy in oct 2002 and it will discharge oct 2005, however i made no mention of this because I thought it was fine.