Blacklisted because of ***** committed by vodacom staff

I had a vodacom contract and was cancelled in last year September 2017 when it ended by October 2017 vodacom still debited my account with a different amount of way more than I contracted for and even though I had called to cancel my contract. When I called in October 2017 I was told that I upgraded my contract and I explained that I never did any upgrade I only cancelled the contract and I insisted that the contract be cancelled. I went and did a reversal of the amount at the bank. After that there were no debit orders on my account yesterday I just learnt from my bank that I have been blacklisted by vodacom for an overdue account with vodacom. I called vodacom and they told me this will be dealt with in 3 days they have found that there was a ********** activity and they are investigating. Now I want my name to be cleared as soon as possible and it pains me that now they have painted my name like that I am very angry I can't help it they turnished my reputation so badly and I need them to take responsibility and be accountable for their negligence! ? ?