Minutes disappearing without any calls being made

The most unhelpful and unprofessional cellphone network provider I've come across, I'm honestly disgusted by the level of customer service I've received from them these past few days.

I took up a contract on the 5th of June 2019, including minutes I receive on a monthly basis. On the 10th of June 2019 at 11:27 I made a call, and to my surprise, I got a answering machine tell me I have insufficient funds, that call was 3 seconds since I didn't get through. When I queried this with cell c, I'm advised that the call was 49 minutes long, I sent through proof of my call log to show it was only 3 seconds. I've contacted cellc numerous times and each consultant is more unprofessional then the next, accusing me instead of trying to get to the root of the problem and finding a solution. I'm at the point of wanting to cancel the contract because how can I still use cellc when I see the type of service they provide.

Can someone at cellc please assist me with this problem urgently.