Terrible service, technicians ***********

Terrible service. I had fibre installed and cannot get signal more than 7m away from router. Technicians are not competent to assist telephonically. I requested a technician to come out yet calls get closed without resolution. I have escalated to management and still no response. After service is shocking, to say the least. And then they want to shove wifi extender down my throat as a solution. So I should pay to fix ill installation?