Cell C Fibre not supplying the speed I am paying for.

I took advantage of the special a few months ago to update to the 1Gbps download speed. The actual speed varies so much it's not even worth having. My debit order doesn't get discounted for the below par speed. From 31 speed tests since November 2019, the average download speed is 298Mbps. Less than a third of what I am paying for. Some of the speeds recorded were 2, 10,11, 5 Mbps. Yes, 2!! Half the speed of my old ADSL line. Out of the 31 tests, only 2 were in the 900Mbps speed range. I know its best effort but when I am paying for 1Gbps, I expect at least 700 and upwards. Last time I logged it, I got a message saying, they tried to phoned Michelle about the problem. Who the heck is Michelle??