Openserve keep me waiting....terrible service and unprofessional

Openserve were supposed to install a Fibre line for me. They called me to inform me that they will come on Monday 12th October 2020 between 8am and 12.30pm. I took the morning off work and waited at home. Nobody turned up. I tried calling them but no answer. Left a voice message and still no response. Emailed them and still no response. 3 days gone already.