Unprofessional practice, bad customer service and failure to provide letter

I cannot begin to describe my frustration with MBD, its been months of trying to get them to provide me a letter stating an account is closed. I have been in contact with Experian and other credit bureaus who have advised that the matter is resolved in my favour as the account prescribed.

MBD doesn't respond to emails and phone calls are a waste of time because they advise me to contact Network Collections who are now dealing with my account. Network Collections are very professional and willing to help, they have sent emails to MBD for their go ahead to send closure letter and MBD does not respond to their emails.

I am exhausted and strongly considering contacting ombudsman, they are so unprofessional!