Overdue unresolved billing of my account

Vodacom has double debited my account I then logged a call and they gave a reference number and turnaround time to resolve my problem with a note to say they will sms email, or phone, the turnaround time elapsed without them emailing, sms or phoning. I then call in to find out about the status of the resolution one of their call centre agent advised me it was not resolved when I asked to speak to the manager he just hang up. Their resolution will help a lot because it will influence my decision I so hope they stop making empty promises and deducting my money ********ly.