Please explain my British Gas bill change

[user1469565563]

Can anyone explain why British Gas have increased my bill from £2100/year to £2800/year, despite me being in credit?

I must be missing something. I pay £175/month for both Gas and electricity on a fixed Turriff plan. I am in credit of £271 as it is summer.

Why then, is my bill going up to £233/month when I have credit on the account?
Thanks for your replies. Im just frustrated with the COL at the moment.

I just pay monthly, with Ecotricity, easy with smart meter, live with cat, slime line dishwasher every 2 days

It's usually due to the system's automatic calculator based on about 30 factors where it only takes one to be a bit dodgy and cause it to be well off. If you think it's not price rises, then you should just be able to change your direct debit amount online.