If the switch room contains meters, it has to be accessable to the supply authority to read the meters.
There is a “standard” key that should fit all switch rooms, and all electricians should have a copy of it.
If the SM or OC has changed this lock and the meter readers can’t get in, then your bills might be “guesstimates”.
There might also be issues during a fire or other emergency if emergency services can’t get access using the standard key.
If they have changed the lock and you have to get a SM contarctor, then perhaps the OC should pay the cost