Amex Credit Card Complaint

Amex Credit card department,

Billing disputes California

I paid off my - - - and cancelled my account in - -. In - - I received a letter from them referencing a credit refund check for $220.00 sayting the check has been paid. Beginning in - and every month since I have received a statement from - saying that I owe increasing amounts of money ( apparently they are adding fees ). I contacted them but was referred to - - in -, Arizona. At first someone there said they would get back to me. They ordered all of my charges for a year. No where did it appear theyre were unpaid charges ( this came in - very heavy packages ) Then in - I spoke to someone name - who said he was filing an inquiry as well. ( I have his details if you need them ). Then in - I received another statement from - - saying I owe $370.00 but that nothing is due, and a note saying that there is a billing inquiry in process. The next day I received a check from - - for $370.00 with a memo saying crdit balance refund. So naturally I thought there had been a mistake and they actually owed me the money. Now today I received a statement from - - saying I owe them $740.00. I called - at - -. They can not help me because the " inquiry is still in process ''. - - will not talk to me because they say my account is in " Collections ''. What do I do now. Please help.