Bad service

I've been paying my Vodacom account in store but to be able to qualify for my upgrade as stated I must pay via debit order. In August I call vodacom customer care and give my banking details and to be debited last day of the month.31 August the amount of R75 goes off. On the 1 September I call vodacom customer services and ask the lady is it the correct amount as it is a lot less then what should have been debited. I an informed no it is the correct amount. On the 6 September I receive an sms I owe vodacom money. On the 7 September I call customer service 111 and account 1946 to find out what is going on. The wrong amount was debited. I inform customer service aaccounts that this is not my fault amd I have spent the money. We set up an arrangement that I will pay it off over 4 months. 11 September I phone 1946 to confirm the arrangement and am told yes 4 months. Today I call again to make sure as my debit order is going off tomorrow evening. To be told the full amount and my last month account total will be debited. I speak to Zolelo a team leader who was so rude and stated to me that no arrangement has been made like that and they would never make such an arrangement.