I went to the doctor XXXX/XXXX/15. I had a {$72.00} co-pay I owed for a dermotology visit. I intermediately paid it when I received the bill ; paid XXXX/XXXX/15. The doctor 's office took and cleared the payment. Then they say they ca n't find the payment. I called to clear it up. They said to fax in proof of payment. I did that. They submitted the account to a collection agency. XXXX/XXXX/15 I received a bill from the collection agency ; I have a collection company trying to collect on an account that has been paid.