@Abbiexoxo   The picture you attached is not your bill, it's from your app, and the app often goes wrong.  No need to worry about your December data  but fuel prices are definitely increasing. 

I know I have the same issue! I joined to this company in October/November and they sent me an email that I have an outstanding balance of £576!!!! I paid £63/month so far and now they increased my bills to £179!! I am living alone and I have no idea how I am gonna pay this mothly!! This is nearly 10% of my salary! My highest bills was £87 before I joined them and they wanted me to join them for less they even said oh thats a lot what you are paying etc bla bla bla… now I ended up with them and with a massive monthly bills! Avoid this company I also want to leave as soon as I just can!!!! Biggest mistake in my life🤬🤬🤬😭

I have the same issue. How did solved this problem ?
It’s because they forcing to get the fixed price tariff( they say energy prices are raising up) and there is 8 p / kW . but with the standard tariff people pay only 4p/ kW. and with the UK price cap you will not pay more at least 1 April 2020

@Luu   You don't have to move to a fixed price deal, stay on your variable price which is capped and protected until April 2022.  After April stay with the variable deal even though it will be expensive because it will still be price protected.