Used BT - never again, brainless f*cktards charged me £258 for 2 weeks' supply of internet and cut me off saying I had used my allowance...on an unlimited downloads contract! PlusNet is BT. Vodaphone when I cancelled my contract still tried to bill me for no supply without telling me I owed them anything, which they reported as a default on my credit score and took 6 months to notice (if you haven't already - check!) took 3 weeks to sort, no apology, or to the email from their customer services stating when I cancelled that I OWED NOTHING.
I have Sky/Virgin here where I live in the smoke and plenty of others. Virgin is very expensive, but they have the best network. Sky uses Fibre near here, but no one can get close to the up/down of Virgin (no pun intended). Just renewed last week for £44 a month for the 500 gig package, didn't want the phone so left it off, and also being with O2 via mobile, I get those offers also. Had 2 outages in 18 months never more than one day, and no compo offered. The only issue was when I got them to re-connect, they disconnected my neighbour to give me their supply during lockdown and then disconnected me and reconnected them, it wasn't a very polite call that I made and was sorted out before I had to even get past the word inept.
I needed the increase in data as my new job requires a lot of working from home.