Query your bill
It’s important to query your bill with your supplier, if you suspect you’ve been overcharged. If an inflated bill is their mistake, you should be able to claim a refund.
Your supplier must respond within a maximum of eight weeks. If they don’t, you can take your complaint to the Energy Ombudsman.
Another way to make sure you’re paying a fair price for your energy is to switch energy suppliers regularly. Use Compare the Market to compare the tariffs on offer and see if you could save.