I took my son to the ER April 2012, provided a copy of my ID. I received a bill for $279 and paid it. On April 15,2013 I reviewed credit report and found $50 collection from NPAS. I contacted them provide my name and they couldn't find debt gave them my sons name and they found that and has my maiden name as guarantor. They also had my address but lacked the apartment number. Staff member states they didn't receive return mail so sending bill to wrong address counts as contact. Manager states they did not attempt to contact me by phone because debt was for a small amount. As of April 26,2013 I have not received anything in writing. In good faith I paid the hospital not collection agency. What can I do to remove this from credit report?