Debt after over 2 years

They somehow got my cell phone and informed me that I had an outstanding debt with JC Penney with no payment since March 2009.  After several phone calls trying to get information directly from JC Penny, asking everyone to give me some backup information on the bill,  what were the chargers for, etc.  NO ONE, JC Penney, GEMB (?) or Recovery Portfolio, said they had no detailed information.  They have filed with on my credit record giving me a bad rating but cant five me any details.  Why would I just pay this without some details.  THey told me to file a dispute letter with them,  but not that I see all of the complaints,  I am wondering if it this even worth it.  But how do I get my good credit rating back.  I ALWAYS pay my bills. Any suggestions?