Over Billing by Vodacom

I am absolutely appalled at how Vodacom takes money and completely ignores you when you want it back . In April I skipped a payment but I was able to make a plan for May . On the 25 of May R947 was deducted from my account . On the 22 of June they deducted R1996! this is ridiculous . I know that they charge R180 for a failed debit order but no one has answer for the excess R869!!! You can’t make such billing mistakes in these times . I want my money back ! I have called the customer care , I have been in the store ! My patience is running thin. I just want to cancel the contract !