Cell C data and airtime mystery

I have been running out of airtime and data by the middle of each month. So I decided to go to a Cell C branch and see what the problem is. My airtime usage for the month showed I had used 100 minutes of 300 minutes, but I was unable to make any calls ! An email was sent to the retentions department about 4 weeks ago to query this, no response ! When I checked my data usage I saw that about 18 GB had vanished between 31 July 2020 and 2 August 2020, with no explanation given for this by the consultant. When I asked for this to be investigated I was told that due to staff working remotely I should rather call Cell C myself and lodge a complaint. This running out of data and airtime has been going on for months but I never thought anything of it until now. I need SOMEBODY at Cell C to let me know what the hell is going on or I will cancel my 3 month to month contracts. If it was possible I would have given a zero rating.