Telkom WiFi Data

I have a contract with Telkom mobile which I took out in July last year an upgrade from 5gigs now 10gigs. It was working very well until it was disconnected in January( no problem with that). Reconnected in February and ever since then my WiFi depletes or it expires on the 21st of each month. When it happened the first time I accepted it because i thought I had used up all my data but now its happening every month and the call centre agents cannot help me they say that there's nothing wrong on their side. The two people I spoke to Smangele and Phumlani Mashinini did not even escalate this issue with their admin department. This cannot go on like this I'm being ****** here as it is suppose to expire month end as per our agreement. I need help please.