Cell c ****** me my money via my contract

In January 2020, I took a contract with cell c for 24 months and was to end January 2022. The contract was not automatically terminated. I had to call for it to be terminated. I called them on 31 January 2022. I was told that I should give them 30 days notice. I was told that the contract will be terminated on 1 March 2022.

On 8th February I received an invoice with amount of R320. I was shocked because I was paying R189 per month or just roughly R211. When I called them, they told me that my contract had a discount but that discount won't be effected for February, it ended in January 2022.

I found that very unfair and dishonest because they "extended" my contract (I had to call for them to terminate it) but the term and conditions of the contract were changed to benefit them. I am very disappointed in cell c and a very unhappy customer. I feel like they are robbing me. And the worst part is I am still expected to pay for March 2022 as well even though the contract will be terminated on 1sr March 2022. Cell c are dishonest and deceiving