Cell C Fibre is just useless

We are trying to cancel our Cell C fibre contract. We received confirmation with a ticket number stating the date of cancellation. When it did not happen, we phoned the call center and got the response that we should have reminded them to cancel the contract. What a disgrace for customer service. We are informed that we should wait 24 to 72 hours and try again to cancel our contract. We want immediate cancellation! I am working from home and is regularly on teleconferences. Most of the time the connection is so unstable that I have to log in several times during a call. This is embarrassing. Please do not ever use Cell C Fibre.