Being an IT guy I get involved with setting up (and dealing with problems) for all major ISPs. I can honestly say experiencing problems with BT Total Broadband are far and away the worst.

You get fobbed off, told to ring various different departments (all overseas). The technical team say they'll phone back and never do. When you call them back, they go through the same procedures again and again (line test, check router, etc) even though you explain that it has already been done. You ask to speak to a supervisor, the supervisor's is "busy" (what a surprise!). Of course, they will still bill you even though you are not online.

There is no co-ordination between departments, nobody who actually has any knowledge outside the script, and expect several weeks and long phonecalls before any resolution. Choose BT at your peril!