BLACK LISTED EVEN THOUGH ACCOUNT IS PAID!!!

We have being paying cash into the Vodacom account at FNB since last year as NO one at VODACOM could assist with the debit order going off on the 28th as per our request!!! I call the call centre last yr and recived the account number that I needed to use, and was told that the ref number is the same!! only to find that my payments EVERY month are not being allocated!!! no I cannot find 2 of the slips that I deposited one from last yr and on from this yr and the account was handed over and blacklisted!!! I have since being in contact with Nimble collection service since last week Wednesday 09/09/2015 and am getting no joy, every time we call they still keep telling us about the payments outstanding but I have sent the email 3 times and faxed the proof of payments... GET THIS SORTED OUT!!!