We are with EDF on a smart meter. We are £978 in credit, yet EDF won't let me put my direct debit down when I try doing this on my account. I got fed up and emailed them saying £978 is too much to be in credit and we are suffering financial hardship. Within 24 hours we had £500 put back in our account.
Moral: Email energy companies and ask for your credit back. Why should they be holding so much of our money?