Continental Finance Mastercard Matrix Discover --Closed Credit Card With $0.00 Balance. Claimed I owed $329 Sent To Collections Internet

I had this credit card to re-build my credit. Paid it always on time for over 6 years. I finally decided to pay it off and go with another card that offered my no annual fee or monthly fees. Last September I made my last and final payment of $80.00 and I closed the account with a $0.00 balance. Now it's February 2013.  I pulled a credit report and it shows a balance of $329 on my closed credit card. I immediately called customer service and they told me that I owed them $329.00 and it was charged off and sent to a collection agency. I argued with them repeatedly and told them I paid the account off and closed it last year. They were extremely rude and gave me the corporate fax number and said I had to fax them proof I made my final payment to them. Strangely on my credit report it shows I just owe the balance and that the account is current. The account does not show Closed By Consumer. Yet I logged into their website pulled all the transaction histories and it shows a $0.00 balance for October thru December 2012. If the account was still open I would have been billed their $50.00 annual fee and $10.00 monthly maintenance fee. The rep I spoke to over the phone did confirm my account said "Closed by consumer request last September.  I am really frustrated while I sit here and stir and wait for them to contact me. I have no other choice but to wait and PRAY they resolve this. The reprisenative at customer service would not even give me any information on the collection agency they supposedly sent this charged off debt they claimed I owed. I would like to sue this bank for fraud. I am trying to find any legal action I can take against them if it ends up being reported as a collection on my reports. I never once received one phone call of any balance, past due owed, a collection letter from any agency in the 5 months since I closed the account. If anyone has any advice on what I can do to take legal action please reply. Never get a credit card from this fee harvesting bank. There will be no way to contact them if you have an issue with wrongfully being billed on a debt you don't owe except sending a fax. The BBB has over 99 complaints filed to date.