Oh, man, am I with you. We moved here Sept 8th and I just got my internet hooked up 2 days ago, and only after haggling with BT/Sky endless hours, dropped calls, running out of my "top off" on my phone repeatedly, and finally working up the chain of command until they got BT to show up. Sky is my new "evil empire", replacing AT&T in the States.
The only thing that saved me was the "MiFi" my husband bought me from 3. Cost something like £15/mo for 5GB which was enough for me to email and do web searches, but not upload lots of pictures or anything. And now I can use it for mobile WiFi, since I have dropped the evil AT&T, and am using an app called "Line2" to make free calls to the states (as long as you have WiFi). BT sure has a lock on this country!
Good luck! Be a squeaky wheel.