Terms of contract not being upheld

I am struggling with MTN and the constant lack of knowledge and assistance from the customer service call centre. It takes hours to explain the issue and before any one resolves or reverts, the query is closed by SMS. I was referred to *****, where I did the same and the query was closed. No one knows what is going on. I am paying for 8 contracts for family members, and the terms of the contract are constantly changing from month to month. I am the main account holder and payer yet all communication gets sent to my dad. In Dec 2022, within an hour 40gbs were gone. I called immediately, and MTN could only account for a gig or 2? Since December I am getting less data on a contract that was renewed over two years ago for a three year period. I have SMS and screenshots but no one can account for the monthly loss of over 50gigs which is now consistently happening.