Voip Minutes not used based on Mweb faults.

My Account no is ***2, I opened an account with Mweb for VoIP minutes for a monthly purchase of R119.00 incl. VAT, for 300 VoIP minutes the Contract start date: 28/Sep/2021. In order for me to use the minutes, I had to download an app from Playstore Called grand stream after that I tried to set up the app it was not verified. I then called IT Support of Mweb and explained what was going on. The technician said it need to be verified on their side he proceeded to guide me through the process of the setup but it was not registering on their side. I called them 3 times to register and I went through the same process and was not successful. On 24 November 2021, I called the billing department explained what is happening, and canceled my service with immediate effect. I was then told by the billing agent that in order for this service to be canceled I will need to wait for 30 days, which I will be billed again in December 2021 even though I could not use the 3months of VoIP minutes and was told that this is their terms. I have paid October and November amounts only. Now I received an SMS stating that if I don't pay the full amount I will be handed over to Credit Bureau. I am not happy with the services and behaviour of Mweb.