Thanks. I'm with Homeserve - they simply do not possess those keys. I asked them why, & they said 'Because they are Bournemouth keys, not HS keys'
Recently, I called out an independent plumber in an emergency, he had the proper key, long slender silver one, with T top. That meter point had been used so many times, it was working loose, the plumber had difficulty turning the water back on, from it. This was 3am in the morning, by torchlight, in the road. I complained to Bournemouth, they sent a man round who started fitting new screws into the meter, I said it should be replaced, he said they won't because it's too expensive.
Neither HS nor the plumber could locate / activate the sink stop-cock. This has been going on for 10 years.
Now, that water meter was not here when I moved in, Bournemouth Water fitted it about 5 years ago, they just turned up in their van & fitted it, don't remember much about it, it was fitted very quickly indeed. They did *not* leave me a T key for it. I just spoke to my neighbour, who's a builder, he has never had a key for his water meter either.
I'm still working on this.