I was sent a bill from a collections agency regarding old medical bills from 2006 and before. I called the creditor and stated that I was unaware of these bills and asked why I was being asked for payment since all but one are older than seven years. The creditor stated that the hospital has no statute of limitations. I checked all three of my credit reports and the only bill listed is from 2006, and it was only listed on one of the three reports. Since the bills from before 2006 are not listed on my credit reports, am I obligated to pay them? Can they put the old bills back on my credit reports?