Double-Billed me 3 months in a row!!!!

I have been a loyal DSTV premium subscriber for several years and have never faulted on my payments. Imagine my surprise when I received a call from a debt collector, demanding to know when I will pay the outstanding amount on my DSTV account. I checked my transaction history online and discovered that you guys have been billing me several times in one month (since July), for my single subscription. I have made countless calls to your call centre, spoken to over 10 agents, each of whom have promised to have the matter rectified by the end of the day. A complete mess has been made of this account. Double-Billings, Incorrect reversals - it's just a mess. So even though I initially had a credit in my account and have been paying the full subscription every month, I know somehow owe R980.

I am tired of calling in- because every time I do, I get the same empty promises over and over again. I find it extremely unfair that I have to be put through all this stress and not to mention embarrassment (never in my life have I been contacted by debt collectors before), when all I've done is been a loyal subscriber.

Can someone who actually knows what they are doing please sort this out urgently