Pathetic service

My Woolworths credit card: *** was handed over to MBD for collection. I have since paid off the outstanding balance and provided proof to MBD. They have been giving me a run around and have not issued a paid up letter to me. They said I must contact Woolworths for paid up letter, when I do, Woolworths says they can't assist since the account is no longer with them. It's been over 2 weeks already of calling these 2 companies to resolve this issue. The account is paid up and I need to close it and be issued with a paid up letter. MBD says it's Woolworths responsibility to close and issue the paid letter where else Woolworths is saying it is MBD's responsibility. I'm tired of following up on the daily basis with these companies. I just to close the account and be issued with paid up letter