I pay my dual-fuel supply quarterly to EDF by BACS transfer, after receiving the bill following a meter reading I give them. It's worked well for years (I never use DD).
Late last month I got an email to give them a meter reading by 6 October. I immediately submitted it online as usual, but on 5 October got another email repeating that I needed to give them a meter reading by 6 October. I tried submitting online again, but the system would not accept my reading as it "could not identify the meter" for some reason. I tried Chat to sort it out, but that was automated and useless, so I phoned them. I got someone fairly quickly and gave him the meter readings. He said he could let me know the bill and that if I wanted I could pay it online by card. As there seemed to be problems at EDF it seemed sensible to get it out of the way, so I paid by CC.
Today I got an email which said "Thank you for storing your payment card details with us"! I did *NOT* give them permission to store it, so I've just got online and deleted the card details. I suppose I should be grateful they let me know they'd stored the details!