Wifi connection and dsl connection issues

So our internet has ALWAYS been band and good. When it's working, it works great!  When it is bad the wifi broadcasts goes in and out  the download is at 12 the upload is at .2  NO MATTER how many times I call and go through the pointless troubleshooting, that I have already done myself, they NEVER send a tech out to look at the lines or anything!  Last year I FINALLY got a tech out and there was some problem that the customer service people didn't see. So he fixed it and it worked GREAT for about 2 months. Then we had a flood and it hasn't worked right since then. Paying $200 a month for stuff we can only half use.  Does this multi-billion dollar company care? NO  that's change in a jar to the CEO  if I can't get it working the way it SHOULD wrk I guess we will try Viasat  see how good the satellite internet is these days.  

So what do I need to do to have a tech actually come out and check lines and equipment??