Failure to issue clearance letter.

I am very dissatisfied with the level of service from Debt Busters, I have shared with them all the paid-up letters, however it has become a mission for them to send me the clearance letter/ certificate. I have been taken from pillar to post for just a mere paid-up letter. I don't understand why it is difficult to issue the clearance letter after having share paid up letters with them. Instead, I am being told about the accounts I settled more than 5 years ago. This kind of service is honestly unacceptable, and it shows how inconsiderate debt busters workers are.