no helpful tellkom alberton city

my son has been having endless problems to sort out his account in january 2024 the account was sorted we even paid extra now 2 months later owe 6500 and the payment that was done in january wasn't even showed on the statement. He pays 1000 every month and we just not getting this sorted he cant pay but debut orders cant go through so he pays cash every month i don't know how more to help and the telkom alberton city us not very helpful or explaining so we can get to the problem solving this matter