Terrible 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. MBD need to issue a paid up letter to me. 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