No forward planning: a dozen bad eggs for Dischem

How is it possible that a pharmacy chain the size of Dischem can 'run out' of the popular beta-blocker, Purbloka over Christmas? All industry shuts down EVERY December, and many patients require this as a chronic medication. So why is there no actual planning to ensure a constant supply? Don't your computer systems work? How dare you shrug shoulders and say 'sorry can't get it'? We expect that sort of laziness from State Hospitals, but NOT a large private pharmaceutical chain. I read that Aspen 'expect stocks in March 2015'. ***, fly stocks in from somewhere.