VODACOM PAY BACK MY MONEY

I app**** for an I phone 11 because it's in my budget - when I went to get the phone the woman said to me, sorry, she made a mistake she only has an 11 pro. I cannot afford to pay more and insisted on paying the amount for a I phone 11 which she agreed to. For three consecutive months, Vodacom deducted R1189 from my account instead of R829. We went to Vodacom and reported it, they said they will pay back the two month's I paid to much and will only deduct the correct amount for September 2020 which was not the case.