Incorrect contract

On the 25th of September 2022, I took a sim-only (100G Data) contract with MTN, split as 20 anytime/20night/60 youtube. After 1 month I realized that the package I am on is not what I purchased. Went to the store (Melrose Arch), the first week of November 2022, to inform them of such and was told the matter will be addressed during working days since it was a Sunday. Went back again seeing that it is more than two weeks and nothing has been done and was given the name of a grossly *********** so-called supervisor, who "promised" to have the matter resolved expediently to date nothing has happened. The salesperson confirmed in front of his supervisor that it was his fault, MTN wants me to pay for an early upgrade or a cancellation fee, for something that is not my fault. Being a conglomerate doesn't amount this organization to some demigod, these companies are ****s to the core. I will pursue this matter to the last end.