Or Staines, or Uxbridge, or Hayes, etc.

you can do it yourself, i think it was press buttons simutainiously but i can't remember how many times.

I've done all that - no response whatsoever.

dead battery maybe?

No. Checked it and replaced it anyway. I bought a new casing for the fob, and when I swapped over the internals it stopped working. It seems likely that I damaged it, and if so, I need to get another. I can buy one on-line for £25, but I don't know where to get it programmed, so I asked for suggestions. I can find places on-line, and if necessary I will phone them all up and get the cheapest, but I was hoping to avoid doing so.