Yes, a normal disconnection here would be done by pulling the service fuse, then replacing the empty carrier and resealing it. Remember that all services here have a main fuse at the point of entry and ahead of the meter (or, of course, three fuses in the case of 3-ph).
If the PoCo couldn't gain access to the inside of the house, I suppose that ultimately they could isolate in the street -- Fairly straightforward if it's overhead distribution but not so simple in most urban areas with underground feeders.
I think there used to be some law that they could apply to the court to gain access to their equipment if all else failed (everything up to and including the meter is their property). I'm not sure how that's altered now that it's all private companies and the old regional "Electricity Boards" have lost their former official status.
