No contract but still debit my account

This is the worst network company to get involved with. After being contacted by an agent who advised that my line will be cancelled after their device has been picked up from me, which has already happened and I won't get debited. They still go and debit my account. This is absolutely frustrating. Every month from last year December, I've been reassured by different agents from Vodacom that my contract is over and I won't get debited. But to this day, Im still getting debited. And because it's over R500 I have to contact the bank and do a reversal which costs me R45. Will this nightmare ever end with Vodacom. I truly truly regret going with Vodacom. The agents are ****s. They don't even send a confirmation email.