Account Paid off and refuses to give letter confirming it is closed.

I paid off my outstanding account in April 2024 at the Truworths store. I have been requesting letter confirming that the account is closed and the truworths head office ( Tasnees S) who keeps answering my emails refuses to give me the letter and tells me I must deal with MBD. they in turn says Truworths must send me the letter. The account was paid off directly with the store and no money was paid to an external party, so please can I get a letter confirming account closure with the company I had an agreement with and that I paid. These games are just not worth anyone's time as you can see on record that this account was paid at the store as directed by MBD at the time. I dont want to be charged any more fees if this account remains open and there is no proof that it was closed