close before the time

Went to bank on the 8/7/2015 at 16:50 bank was closed I asked the security pointing to the time in bank that it was only 16:50 he said his not sure as he was told to stand with the man that is busy with ATM. We got the attention from the staff member we asked why they close so early he pulled up his shoulders. I asked him to call manager I asked him what is happening coz she taking long he said she on the phone. Eventually she comes out I asked her why bank closed so early pointing at the time it was 17:00 I called the security to conferm we are standing there for ten minutes and so he did the manager looked at him very upset and told us well we follow the time of PC really lol and I told her time in bank is the same as my phone. She said well lodge a complain if she is a manager she needs customer service training. However shops close to bank conferm the close earlier sometimes.