MTN UPGRADE RESULTING IN OVER BILLING/CHARGING OF NEW CONTRACT AMOUNT

I was contacted telephonically by mtn consultants that i was due for an upgrade as I was left with 2months on my previous contract so due to convenience i decided to do the upgrade on 12 September 2023,. My previous contract was on the Sky bronze package as is the new upgraded contract with an S23Ultra. I was informed that my new contract would be at a total cost of R1789 per month for 36months and that possible pro rata amount would be payable for the remainder of the month of September that end October would be on the above mentioned amount. When I received my statement around the 12th of October the amount invoiced is more than double at a rate of over R4400.00 my new amount quoted. On inspection of the statement, I am charged for my old phone, my new phone, the sky bronze package as for October as well as September even though the remaining of September I was charged a pro-rata amount of just over R1200.00. I was made aware that I will not pay more than the quoted amount which is at R1789.00. During the telephonic conversation they did stipulate that the calls are recorded and recordings can be made available. Is this a hoax or a way of getting people to pay more than they actually should. I upgraded because I was informed that I'm due for upgrade with a month and a half left on my previous contract. Why would I want to upgrade to actually pay exorbitant amounts for both phones. Recordings are said to be made available but struggle to even get mine. I have contacted MTN customer services numerous times but keep get transferred from one department to another no one can assist to get this rectified. Do not quote me one amount and invoice another especially knowing that was not the agreed amount which could be noted as *****. There was also an initial Service Request Number: *** which was Opened on the 17th of this month but still not attended as it related to the querry. I have been with MTN for over 10 years from prepaid to Contract and have upgraded numerous times but now this is deeply concerning incorrect billing amounts. Let MTN go back and retrieve the recordings during the telephonic upgrade conversation with the MTN Consultants. I have also never defaulted on any of my debit orders/ payments throughout my contracts with MTN so I feel MTN should also do right by the customer.