Terrible after sales care

I have a two year contract for a dstv decoder, about three months after the contract started I phoned and submitted via email my new banking details where they should debit the monthly payments from, about three months later I receive a call from their debt collector lawyers, I explained to them what happened and that no one from onairtv phoned me if there were issues before they forwarded my account to the lawyers, and than I also found out that they even reported me to the credit bureau as a default payer, I have tried a number of times to get feedback from onair tv and resolve this and also get answers as to why they failed to update my banking details and debit from my new bank account, 8 months later still no feedback and my name is still on the credit bureau, no after sales care.