EDF: You put up my direct debit by £32 without asking me. You did that in the middle of a very harsh winter, based, I assume, on my energy usage at that time. I also assume that that was a ruse to get me to build up a massive credit balance over the next 6 months so you could earn interest on it. I don't like that idea. So when I call you to revise the direct debit amount, you tell me I have to clear my (small-ish) balance first. I don't like that idea either, especially as the direct debit amount you are taking will easily clear that within a few weeks. I wasn't in the mood to argue with you today, but, rest assured, I will call you next month when the balance is cleared and reduce the DD amount drastically.
And another thing or two: get your operatives to speak during very long silences so I know they are not filing their nails in the meantime and buy them some decent headsets so I can hear them and not what's going on in the background.
I can't see this being a long-lasting relationship, tbh.