Who's your electricity supplier?
I had a similar problem with Electric Ireland where I submitted a meter reading via ESB Networks website but mistakenly I took the reading from the meter next to mine -- duh.
So I got a bill for around €12,000 when the bill should have been around €150 to €200
I immediately called Electric Ireland but their service was a disaster,
-they said they'd put the DD on hold until it was sorted, 2 weeks later they try and payment for the 5 figure sum
-they said send us a photo of the meter reading--- did that, weeks passed nothing happened called them, they say photo needs to have dated receipt/newspaper heading
-they said the reading was a network reading so couldn't be wrong, I say it was me that submitted the reading incorrectly...no reply
-I send in written formal complaint -- no effect
-send another written formal complaint -- no effect
Finally I complain to CRU... a nice lady from Electric Ireland contacts me and problem is solved within 7 days