Beware of upgrades: Unauthorised dedutions from Bank Acc

Both my husband & I recently received SMS's to advise we are eligible to upgrade soon. We went in to Vodacom Somerset Mall to look at the options & the consultant (Johann Boshoff) advised that we can upgrade immediately but we will have a double handset instalment (an additional amount of R289) for 1 month as there was 1 month left on the previous contract. We accepted this condition and upgraded both contracts. It has now been 3 months of double instalments and no help from the consultant or call centre. We want the unauthorised deductions to be refunded.