Fibre line

For the past 3 months I’ve been requesting call outs from my service provider Afrihost and Vumatel to check my fibre line. The network/WiFi keeps cutting off while In use. I have a 100mbs line! I’ve logged over 20 calls and yet up until today no one called back or came to check up on the issue! This is extremely exhausting going back and forth with the 2 and yet the problem has not been solved