Incorrect amount debited from my account

I took out 2 contracts. 1 for cellphone and 1 for data. They was supposed to debit my account twice, a pro rata amount. But they have debited my account four times. I am absolutely ****ed off. Because what we agree on, on the payment agreement and is not what they debit. This is *******. And I wish there was some way I could sue Vodacom, as this is not the first time, I'm having this issue with Vodacom.