Best answer by Nancy_OVO
Sounds like you've had a Direct Debit review. After you’ve submitted a few meter readings, we might see that our predictions don’t match up with your actual energy use. If this is the case, then we know your energy account will be in debt or credit at the end of your contract. To avoid this, we update your Direct Debit amount and let you know, ahead of time. We also give you opportunities to update your Direct Debit amount yourself. There's more information about this process here.
However, this does sound like quite a hefty increase! I think there may have been an error here, either with your billing on with the system we use to review Direct Debits. Please get in touch with the team as soon as you can on 0330 303 5063 so they can look into this. They’re available 8am - 6pm Monday - Friday. Alternatively, you can send us a message to our Facebook or Twitter pages, or email us at email@example.com. They'll be able to make sure your billing is correct and your payments are an appropriate reflection of your usage. If you have traditional meters (non-smart), make sure you have a meter reading ready too, as this will be handy for updating bills if necessary.