I asked to move my direct debit from 21st of the month to 29th of the month which was done via the text service. I was told that I could not change it until February as my January bill had already been issued. This was fine. My bill came out on 21st in full(£89) but I also have a second bill now that will come out on 29th January, this second bill includes the £89 from the bill already paid. The second bill should only be the amount for the extra 8 days and not 8 days and one month. How do I get this adjusted? I obviously don't want to pay twice for January.