Is it okay to complain about overcharging 123 15?

You can call 123 15 to complain about this situation.

Residents can report to the Electric Power Bureau that they have overcharged electricity, or they can directly call 123 15 to defend their rights. If the landlord charges electricity at a price higher than the national standard, the tenant can also call 12358 to report the national price complaint. If you are not satisfied with the results, you can further complain to the consumer association or the relevant regulatory authorities and apply for a solution.