Worst Internet connectivity ever.

I have been an MWEB subscriber for many years and have loved their service until the past two years. I upgraded from ASDL to Fibre and since then - my internet connectivity has been a joke. I'm lucky if it connects. On recommendation from their tech support team, I spent money buying a new router. This made absolutely no difference. I upgraded to a 100meg line - no difference. ADSL was so much more reliable. Most of the time, we can't connect. The wi-fi is useless!! My son had to run a LAN cable from our living room to his bedroom so that he could do schoolwork from home. I work from a home office and use my CellC LTE when I know I have to be online. We've called multiple times. I've logged queries. I've even paid to have someone at my house. I've just spent a long time holding on the phone - desperate for help. I'm at my wits end.