Contact the card issuer to get the charges 'charged back' to your account, they should give you advice how to do this.  As far as I am aware the same rules apply as to the credit cards which although they are to do with the credit protection legislation the banks make the same contractual rules apply to both credit and debit ...

EBICO http://www.ebico.co.uk/ don't charge for the meters either gas or electric and there is no standing charges either up front or hidden in the unit charges. They don't feature in all the comparison sites because they don't pay commission and are a not for profit firm so go to their site and look up the flat rate unit charges ...