Daily Connectivity and network issues after years of service with no problems

I am having long periods of no service after weeks of having random drops in service all day long. When we do have service now the drops are continuing to happen. Prior to the long periods of no service starting this week I had a tech out to fix the dropping issues. He tightened something in the wall and gave me a new modem but neither fixed the problem. His supervisor called me afterwards and gave me his number in case of further issues but he is not responding to texts or emails and because there is a service outage in my area I cannot get a human or even AI to speak with me about these issues when I call. What can I do? Is my only option to cancel service? I work from home and need reliable internet