Why is there an overspending of electricity in a two-story house?

Hello, please tell me what could be the reason, we can’t figure it out! There is a 2-storey house! The house has a 100 liter boiler, an electric stove and a water pump! Residents of the house are at home only in the evening! All electrical appliances do not work all day, but the meter spins 10,000 each month! We are looking for a reason for a long time, but have not been found. But once we tried to connect the devices through the second floor and everything passed, the payment came in at 600! Tell me your opinion, what could it be? Someone connected or some kind of leak in the wires?