MTN complaint: Over promised and under delivered service.

On January 2023 I got a call from mtn regarding my contract with them. They had a back-to-school premotion where by the offer me a laptop with 8 giga bites of data and there for because I am a very long and Loal customer of MTN they are giving me a very special deal. At first, I refused explaining to the sales lady that I have already have two contracts with MTN and I cannot afford a norther contract deal, because my current payment to MTN was 800 rand per month. The sales lady explained that this premotion will be 500 rand in total plus I will save 300 rand I said to her that this is a scam, and I am not interested, she then let me speak to her supervisor and her supervisor ed that this was not a scam. At the end of January, I got a bill of 1300 rand not 500 rand as per discussion when thy sold me the contract. I have tried several times to contact MTN regarding this matter and I know all their calls are recorded up to date no one of MTN has helped me. My phone lines have been disconnected and I have been handed over to their dept collectors because my payment to MTN has fallen behind. I pay now MTN as per agreement set by them and I honour my agreement plus till now no one can help me to get a settlement so that I can be on the air again. I can now only communicate via email and what’s up.