I'm with BT but find their customer service hopeless. I switched to BT Infinity about eight months ago and tried to pay some outstanding funds as the Direct Debit started late in the month.
Went through the usual "If you wish to blah blah blah press 1, "If you wish to blah blah blah press 2 and so on.

After endless attempts to pay them and getting a foreigner that I couldn't understand answering my calls, I used their live message service to ask to speak to someone in the UK that spoke good English. They replied and asked if they could phone me, and when I agreed I got a call..............from a foreigner that I couldn't understand.

Also, when I was with TalkTalk I had a 10GB limit and never went over but now I'm on BT Infinity I'm clearing 40GB. My usage habits haven't changed and I've checked that no-one else is using it so what's happened there? I do not own a gaming system and have no interest in them so it's not that and I wouldn't even know how to download a film.

I find it amazing that a telecommunication company are so difficult to speak to. I don't blame anyone for leaving them and changing supplier.