Don't understand customer service

When one says 5 minutes, you stick to 5 minutes. If not then you can't deliver. Woolworths is suppose to know this, I'm boarding a flight at 5 30, Woolworths is suppose to open at 5. They said we should allow them 5min due to technical issues, it is now 15 min later. Staff are here an hour before opening, why wait till the last to check your systems