Are you willing to name the company in question?
Quite often, much like the domestic suppliers, the company who send you the bills have little to no relationship with the company responsible for accurately maintaining the meter database.
You need to make quite sure that the meter which is on the bill that they sent matches the meter at your premises – there will be a serial number on the meter. Once you confirm to them the meter serial does not match your meter that should stop them taking any action.
If someone came to reconnect the supply, they can at least book appointments with the meter operator to check meter details. This would have the effect of updating the MOP databases, but there would still need to be some work on the part of your supplier to remove the old meter (once the MOP have send the relevant data over).
Makes me wonder if the pub went under due to crippling energy bills, and this was the cause!