No customer service and low speed, intermittent fibre service

We are paying for a 300mbs line and the highest speed we get is between 80-90 mbs. They told me the router was faulty, so I purchased a new top of the line router and have the same problem. Our fibre was down, or intermittent for most of the week, so I cancelled our package and asked to downgrade to a lower option for the months notice period as we are not even getting half the speed we are paying for and it was refused. I have phoned multiple times and been promised a manager will contact me, with no calls. Ive been told to email screenshots of the speed tests, which I did, with no response. Currently I have been on hold for close to 30 min again while they try to contact a manager.

Stay very far away from this company if you expect to get what you pay for.