As an update I have checked the letter for wording and it states, "if we haven't heard from you by the time your first bill is due, we will have to change your account back to our Standard Plus tariff, which is more expensive." To me the wording of this specifies that they will change it back upon the due date of the first bill, but in no way specifies that they will backdate the previous energy used onto the more expensive tariff.
Hey all, This is my first post although I have used the site before (lurking in the shadows) for advice on a lot of different things and now I have a query that I can't find an answer to without asking it myself! I moved into a property back in the end of September 2012 & unfortunately I've been having a lot of trouble with Spark energy. I have contacted them on many occasions as I was trying to receive a final bill in order so that I could switch to another supplier. I've now finally managed to receive a bill from them, however the problem I have is the fact it