MTN SAFE - NOT SO SAFE!!!

I received a call on 5 December 2024 from MTN Safe, offering me additional data on my cellphone. The offer being 200GB for an additional R36.00 on my contract. My contract at the time was R497.39, plus 15% VAT = R571.99. I accepted after a lengthy conversation (which after several attempts I have still not managed to obtain from MTN via various MTN outlets using manager emails addresses). 13 January 2025, I receive an invoice of R740.87, if you add VAT R111 = 851.00. Where did my contract increase just R36.00. My contract has increased R280.00. For six months now, I have been dealing with MTN safe, back and forth. MTN billing, back and forth. Trying to obtain the recording and MTN can only respond by saying my billing is correct. No one can explain to me how my contract has jumped R280.00 - MTN Safe moved me onto a diamond data package it seems. Where "only an additional R36 on my contract" as offered and sold is complete BS. No one is being held accountable. If I intended to have such a high cell phone account, I would have rather taken out a new device for my child and worked with the data I had. I need answers!!!! I have been with MTN for more than 25 years, why are third parties allowed to mess with our contracts without recourse. Prove to me that I am getting what you sold me and I will pay!