Complaining client

Their service is bad, i had issues with the fibre as it got burned over the weekend, then they come today to install the fibre and it worked for 30 minutes and then it started flashing a red light confirming that it does not have internet at all, i send WhatsApp from 12pm with no response, i am being ignored on WhatsApp not even an automated response nothing, having to buy data while i pay fibre it does not make sense, can someone please recommend a better service provider, cause this one is not working for me at all after using their service from 2020.