DSTV : Over billing accounts

I have a Dstv for years & then i changed to pricelock.Throughout the contract there has not been any problems until it was nearing the end of the contract where dstv has been over billing me.I called the call centre countless of times & cant seem to get this problem sorted out.My preicelock contract is done and has reverted to its original plan.In the middle of October i was told i owe R494 & today being the 28 October im told i have a balance of over R2000.But my service has not been suspended.There is a huge problem with their system as they have cut me off before even though there was nothing outstanding and still have the audacity to bill an extra R183 for which no one at the call centre knows why.I called countless times but no one either seems to care,or wants to help & just expect it it to be paid.Who does one really speak to because the agents themselves are at a loss for words & always put you on hold hoping the call will be terminated .DSTV doesn't give a dam about their customers.