Pathetic service from MTN and their store sales consultants

One network I've always advocated for has proven to be unreliable. I have got into my first cellphone contract with MTN in 2020 March. I was then due for an upgrade in 2022 which I did upgrade where I was given the same package. In 2023 I went for an upgrade as it was open from the month of November. To my surprise my package has been tempered and they now claim that the package i was on i was given promotional benefits which that it isn't the case. These benefits we reoccurring benefits and not promotional. How can promotional benefits last for 3 years. I have been liaising with Terrence my sales person at Menlyn Maine store who kept on shifting the goal post. I have enough proof of our conversation where promises were made and nothing come out of that. Up to now he hasn't supp**** me with copies of my new contract. I shouldn't have upgraded with mtn maybe it was better to give a different service provider a chance, considering that I am still within the 30days. My number is ***.