Thank you for your advice and reply’s.
I’ve now checked the electric and gas usage and found that my combined bill for the month will be £755. This is about £300 more than it was last year, when we had a new born baby on the house so we’re keeping it extra warm.
Trusted house sitters have replied to my message saying that they can’t do anything and that I should use the review system.
I’ve contacted the sitters again and tried to calmly and practically explain the extra cost and I’ve asked for help. I just hope that they are as shocked as me at the cost they ran up and offer to help with the bill.