Breach of Contract by Cell C

I took out a data contract with Cell C on or around September 2022.

In terms of the contract Cell C agreed to give me a Variable Discount of R128.87 which i why i agreed to the contract. Howevber , i note on my statement Invoice dated 2nd October 2022, this discount was not given at all. In my opinion, Cell C have breached their agreement and i want this discount credited to me!!!!