RAC Acceptance RAC Rent-a-center Ashley Furniture RAC Acceptance Gives NO Payout Possible/No Ownership in Site Florence, South Carolina

Please help!I am a grandmother trying to resolve an issue with the RAC Acceptance center here in Florence,S.C. I purchased a set of bunk beds for my grandchildren two years ago to date from this company;being told that I was under a purchase agreement and not a rental contract.I custom ordered this bed from the factory.After two years of payments I went to my last payment in July 2012 and was told by the current manager that I had several more payments due.I tried to discuss this with  her but she threatens me with attorneys and wants an additional $500+ dollars.I only owed one more payment of $168.76.  
                                                                                                                                                              I spoke to her last July and ask her what was due on this account and she told me $958.76.As of that date I have paid in over $1700.00.Do the math;I can't figure it out .Please help me.