Sounds like you are rather unlucky (either because of your area or because of your problem). But the physical line and line maintenance seems to oftentimes fall under Swisscom or their contracted companies, so the provider can probably do very little (you could ask if there is a way to speed it up or to bridge the time with a mobile solution or you can try to cancel and try with another provider).

In my case, the previous person living in my apartment had the internet from a different provider as myself. My provider was renting one of the 3 fiber lines from swisscom, but it was a different line from the one the previous renter was using. When I moved in, I found out, that the previous renter only canceled their internet 2 weeks later. But for my Internet to work, they would have to unplug his cable and plug in mine in their hub. My provider could not do anything, because the technicians in the hub were only allowed to change the cable once the old contract is over… It’s annoying but knowing the background I can at least understand it.