To give them their due, it's been sorted. I called customer services on Saturday (had to wait in a phone queue listening to the bloody Mad Men theme for an hour!) and they arranged for a BT Openreach engineer to come out on Monday morning. He gave me a few instructions over the phone (e.g. my particular socket didn't need the microfilter), and also asked whether anyone in the household had had flu-like symptoms, in case he had to come in. Then he went and tweaked something that hadn't been done correctly in the green box outside the house to activate my line. Result: all was up and running by Monday lunchtime.
Seems Openreach engineers are classed as key workers at the moment - which I suppose makes sense, as so many people are now having to work from home.
Hopefully, they'll be able get yours sorted quickly too. 🙂
