Poor Service No Help

I have been an Mweb customer for many years. A number of years ago we switched over to uncapped fibre and from the time it was installed the service has been very poor. The internet is constantly up and down. I have made numerous calls in the past to have this rectified and each time I call the Mweb team say there is nothing wrong with their side and it must be on my side. I have since changed my router and still have the same poor service. Ther service has become so bad now that I cannot even hold a zoom meeting with the service dropping and going down to 2mb in speed. I decided to call again today using my voice over IP, spoke to the operator and yes, the internet dropped off cutting the call. I called a second time and the same happened so I called using my cell. 20 minutes later I cut the call as I was still 15th in the que. Needless to say, after losing the call to the operator, they do not phone you back and it is a call wasted. How does one get any service from this company when you are not able to contact them with a problem? I need to look for a more responsible service provider that you can communicate with.