Fibre speeds not even 30% of 20/20

This ISP Service is supposed to be for 20/20 fibre on a VUMATEL line. Then during COVID-19 Lock down we are supposed to get double speeds 40/40. I and receiving speeds below 5/20 with pings during day being below 5 but at night it rockets to over 400 to even over a 1000. Getting no reply or phone calls from Accelerit. I even cc Vumatel and their support email just bounces back.