back t the original question, I'd check Pooleys or similar for their times of operation. Not got mine to hand but I think ending at 17:00 rings a bell.So that would explain why you couldn't raise them. I think the hours are a faily recent change as I also thought brize lars was a 24 hour operation.
In general check for LARS coverage and hours , as you may get caught out at the weekend in teh summer if retruning late from a destination.
Well worth doing especially if you are planning any IFR flying as you mgiht find tehre is no coverage for your return flight.