Vodacom's frustrating billing system!!!

Vodacom cannot decide whether I should pay them directly or whether they will debit my account. I have been with Vodacom for over a decade and suddenly this year from around March, I have endless issues with their billing system. At the end of May and June, they did not debit my account. I only realised this went I went into my Vodacom app and found that I was owing double the instalment amount. I immediately made payment. The following month, July, I made a payment as they hadn't been debiting my account. About 2 days later, Vodacom decided to debit the same amount off my account so I am now owed R684.99.

I've phoned Vodacom and they asked me to send my bank statement highlighting the charges which I did on Saturday, 7 August. I have yet to receive a response from Vodacom, let alone an acknowledgement email.

I want this resolved once and for all and to have the money refunded to me.