What?! No, no I'm not!
I was all ready to get a major fury on about British Gas for attempting to sabotage the switchover. Turns out, however, it was Eon which was to blame. I remember an Eon salesperson coming round recently and trying to con their way into switching me over ("no, I'm not selling anything, I'm here to carry out a price comparison..."), who I ended up having to shut the door on because of their persistance.
The team at EDF Energy have been nothing but professional and helpful about the whole thing, though. They've given me employee names and direct lines to call, and are not only trying to sort things out their end, but are also corresponding directly with Eon about the issue. Best service I've ever had from a utility company.
As far as they can figure out, it is in fact somebody else in the same area who has signed up with Eon (guess the salesman got one scalp, then), and there's been some sort of address mix-up. I suspect the classic Edinburgh "x/y versus y/x" confusion. It does my head in.