OPENING OF STORE

I arrived at the store at about 3 mins to 9 this morning. I was in a hurry because I had an appointment at 930am. Three staff arrived at 9am, unlocked the store and went in,locking the door behind them. I pointed out that it was 9am and that the store should be open. The one assistant turned over the store hours to reflect a sign that said that the store would open at 930am due to staff training. I knocked on the door and said that you can't have staff training on a Saturday - I have never heard of that before. I asked again what time the store would open and I was told 930am because they still had to sort out the tills etc. I understand that they would have needed to switch off the alarm etc and I was prepared to wait for 5 mins. On the other hand should they not be at work earlier if the store opens at 9am? I was actually speechless and just walked away.