Seems like you are using a lot of electricity for sure . Air conditioner set at 24 degrees will reduce the usage . Instant hot water services use much power . I would check that the meter is working correctly
You are paying 2,5 baht extra per kwh to the landlord . There is a law that prohibits landlords to put on extra . If that law applies to your landlord is hard to say .
200 baht for water is also steep for a one bedroom apartment .