Sales reps paid to trick you

I have two accounts with Vodacom, I tried canceling the one (R 80 p/m) as I no longer needed it and the salesperson offered to help make my remaining contract (R 225 p/m) cheaper after I explained my situation. He explained that I needed to pay the settlement amount and submit proof of payment to Vodacom for the cancellation to go through, which I did. I then received my monthly statement saying that R 303 would be going off my account, this didn't add for me but I assumed it was a final payment or something and chose not to say anything, then I got an sms saying R 364.97 would be debited from my account. I double-checked my statements and there's nothing about this extra amount, but the amount came off anyway. I now received an email with a quote to migrate my existing contract to the new one (R 225 p/m to R 130 p/m), it says I have 30 days to accept the quote and I have to call Vodacom to accept it. I can't get through to Vodacom and considering I did the whole migration/cancellation request two weeks ago and accepted the quote over the phone, I'm more than frustrated with the fact that I have to struggle to get through to accept this quote AGAIN and that they took nearly double the debit order amount this month with literally no explanation. I would like both contracts canceled at no charge to me, as it seems they take as much as they like when they see fit and don't even provide a reason, and I am no longer interested in using any of their services.