Still no stable connection after a month of back-and-forth

Mine is a long and frustrating story. I signed up with Webafrica a month ago and the sales service was fantastic. Mitsol came an installed the fibre line, the courier delivered the modem, and then, nothing. I connect to the WiFi long enough just to get my hopes up, and then I get dropped. After trying to deal with technical support both through the chat service and the complaints division, the same instructions just get sent to me over and over. I've now performed these instructions so many times, and wasted a ton of my own time. We've only switched three devices over to the fibre line, and ALL THREE devices keep bumping back to the DSL line because the fibre keeps dropping. One of the agents recommended a new device because there's something wrong with the WiFi on this one, but nothing has come of that. The other issue is trying to get hold of someone at Webafrica. Everything diverts you to the WhatsApp chat service and it takes at least two hours to be attended to. Sometimes you'll get a message to say "it seems there has been no communication between yourself and our live chat agent for quite some time. This chat session has now expired but if you'd still like to speak to an agent again, please start a new live chat session. The new agent will have a copy of your last conversation." This after you've given the agent your whole life story. So now, you have to start the two-hour process again. Pathetic! According to Webafrica, there's nothing wrong with the line. So what is the other logical solution? I'm fed up and want to cancel.