Horrible Connectivity

I am just not having joy!! After numerous service calls, and attempts to correct my connectivity, changing routers etc. I still get horrible connectivity, so much so that I change over to mobile network on my phone & have to connect via tethering with my laptop, absolutely ridiculous. I have to reboot my router constantly while they recreate my port, i have my line with them now as well due to excuses that they can't do what they need without it, & still no better. Now looking for new ISP!!