Debit order

I so not happy with vodacom Last month a consultant called me told me to add 55rand will receive 175 the amount that i normal paid for I agree and we agree it will be debited on the last day of the month which was yesterday but If I'm checking 474 was taken instead of 372rand and on top of that i received 176 airtime i called to vodacom customer service i spoke a consultant who didn't even check or asked me security questions told me it not reflecting but ont the 7th of September i received an invoice stating i will pay 372 and around 28 September received a email saying I'll pay 472 and they were not specific about it and if I'm checking on the 31 October I'll be paying 474 i don't understand what is it for please assist, this is not the first time vodacom take money and give you lame explanation that you won't understand with their attitude