CSS is Comtting *****

I have a contract with MTN that I can not afford to pay since the start of 2021 because I have lost my Job in December of 2020 , so now I had an agreement in place with CSS Solutions, their debt collecting agents to pay a Minimum of R200 Per month to pay of the debt of the contract. However ever since I started paying The agreed amount of R200 starting December 2021 ….My total outstanding balance does not go down, in fact the balance keeps going up..... The money that I paid since last December 2021 DOES NOT even show on my statements from MTN..