Debited after account settled with No refund

To say the least the service I have received has been pathetic. From the beginning I never got my monthly statements and had to request a statement every month and only get a response 2 to 3 weeks down the line. On the 20th of November I settled my account and requested a paid up letter which I am still waiting for! On the 25th my account gets debited. I have called and sent emails and nobody replies. Please may I have my money back and letter confirming that my account is paid up because I am tired of your incompetence. And I actually shouldn't be shocked judging by the nature of complaints you are receiving here on Hello Peter. Hopefully on this platform someone will decide to do their job and send me the requested.