Submitted readings on 17/02/2022 balance on account was approx £500. Just did it today, 3 weeks on, same level usage, account balance has now suddenly jumped to £2002!? I assume I gave the right meter reading for elec, it actually prompted me to say this looks too low? Has my balance simply changed to reflect the variable annual tariff?? Could the reading I gave be wrong? I'm shocked and confused. Thank you.