The issues is the lack of instruction on how to use the lock mechanism. A simple "number code" is not enough. It takes several physical moves to get the door open. A team member showed up 30 minutes later to instruct us on this rather arcane method.
Also, if a customer gets there a half hour early, and the lock mechanism is set for a specific time, the customer still can't get in until the appointed time. A little slack would be helpful as most people on holiday wont be EXACTLY on time.