Incompetence

My husbands account was handed over to Shapiro shaikh Defries & associates. They sent us a settlement letter with bank details on 29 July 2015 which I paid in full on the same day. I sent the proof of payment to them several times but we were still receiving smses and calls regarding non payment. We went in to Edgars only to be told that the account number supp**** is unknown. After several enquiries with Ssda they advised that they gave us Nimbles bank details in error. After several more queries I was told I had to now supply my bank statement inaddition to the proof of payment they already have with my certified Id and a letter requesting refund. I did not make the mistake. The attorneys did but I sent the additional info on 12 October 2015. Again despite several enquiries I am still waiting for a resolution. Iloza msimango from ssda replies when she feels like and then only to say they waiting for a response. I don't see why we need to be inconvenienced due to other's incompetence. I just want this account closed, his Itc updated and the paid up letter as it is 4 months later with no joy.The account number is ***