How many times does Vodacom want me to pay?

On 4 May, I was notified by sms that my account was debited with R825 which is more than double the amount I usually pay. on 4 May,13h48, I phoned Vodacom to query this. I was told that double the amount had gone off because it had not been deducted on the 1 April. I checked my transactions on the 1 April and confirm that 397.50 was in fact already deducted off. On the 5 May at 11h55, Vodacom sent an sms informing me that the wrong amount was deducted and that this would be resolved. At 18.00 on the same day I get told that the error will be reversed. Today, 7 May, I get notification that another 397 has been deducted. Please can someone tell me what is going on with Vodacom. I have now paid R1 222 for a bill that is always about R397. Can Vodacom get their act together please!