Deduction was incorrect and I was **** to

On the 7th of June I contacted the Call center to add a new line to my contract - a 1G Data Contract with a Wi-fi Router. Ref number ***3 - the Lady Michelle told my that a pro-rata amount will be deducted from my account, I asked her what the amount will be so that I can ensure that the debit order will go trough, she said she is not sure but it will be less than R99 because it will only be a pro-rata amount, I specifically asked if there will be a sim and connection fee and she said NO, the next day the 8th or could be the 9th I phoned again and I spoke to a gentleman, I asked him the same question and he said there will be no sim and connection fee. So I made sure that there will be enough in the account for this pro-rata amount which will be less than R99. When the deduction went of it was the amount of R150 and the amount returned because of insufficient funds!!!! I was **** to and feel very very disappointed. I always liked Vodacom as my connection provider, but not anymore. Now I must pay R100 banking chargers because of the failed deduction (which is not my fault and again vodacom) - I claim that this amounts will be settled and paid by Vodacom self and not by me!!!