MTN Data contract

Good Day.

I am very angry and disappointed in MTN, I have a Online data contract with MTN and studently end of May 2023, I received only half of my data as per my contract. every time when I call customer care they lock the claim and said they will call back with feedback. So MTN are selling contracts and then during the contract period they change data as they want with out even informing me, but my installment stays the same. So this in contract break because this is not wat i signed up for.