Wrong Amount Wrong Debit Date

I took out a new contract with them Aug'17. The time i took it the phone was on special at R199.00 . I asked the lady numerous times if this is the amount nothing else she agreed. They activated the contract in Oct'17 where they debited me R225.00 on the last day of the month when I told them the 26th is all my debits for my cell phones they need to take it that time as well. I have been phoning since last year Sept and they keep telling me it will be sorted out. Every month they deduct the R225.00 which was not agreed on . I have not used the sim number as the contract is wrong. I'm now tired of hearing I'm escalating We will phone you back etc.. That is all i hear and every month they deduct the incorrect amount. I need my money back and I told them before to collect they phone if they cannot resolve this . Up until today 06/02/18 I'm still waiting for someone to call me back