Just given up...
Firstly they lost access to my O2 account stating my email couldn't be found. Customer service sent me to a shop (68mile round trip) who said they couldn't help. Then O2 disconnected my SIM despite my PAYG account being in credit (notified by text as usual when I used the phone) -without notice...because I didn't make calls (they said). 'Perfectly' legal (they say). I used the phone for security and backup -. Why not send a text to advise they were about to terminate the account? Not difficult.
Customer services advised I open a new account £0 in that of course.
The mast here is old tech...we were disconnected for months last year because spares were hard to get. (The landowner met the engineers).
The Govt should be paying more attention to services in rural areas and the way these 'petty gods' behave, options are often limited and signal weak/non-existent, particularly as landlines are due to become obsolete. Mobiles are becoming increasingly essential.
I have absolutely no faith in Ofcom.