"I've just double checked. Last reading on the meter in question was a smart reading which was on the 26/10/23 and was 16970. The reading i submitted today was taken on 24/11/23 and was 21125."
At least one of those might be wrong. To make sure that hi@eonnect.com look into it and possibly check meter reading procedures, rather than accidently putting through a massive overcharge, it might be useful to poke around with your internet banking "payments to people you've paid before" "direct debits" "manage". They'll squawk, but my October bill was less than 35 pounds; you should probably not be paying more than a thousand. Some smart meters have a lot more numbers showing than the relevant one from which your bill should be calculated. Not my subject, but do ask someone. For example, if you had read a big gas number and sent it off when you'd been asked for the other electric number. If that happened, then your electric bill could be recalculated to the next smartmeter electric read.