Horrible service at reception

There is a query on my account I needed to go follow up on this Friday afternoon at the CSS Security offices Klerksdorp. From my previous visits there I know they close at 5pm because I work till 4:30pm then I would still make it before 5pm and would be assisted. Unfortunately I did not know that on Fridays they close at 4:30pm. I get there 4:45pm and I see a lady inside so I open the door to ask if may I be assisted as there is no sign that shows its closed and no operating hrs put up on the door. This old lady rudely shouts at me for opening the door. I tell her that I just wanted to enquire if they are still open, she then shouts and says can't I see the door is closed. I responded that all the times I've been here the door was always closed, esp that it's winter, usually doors are closed one just opens to get in. She then shouts that can't I see the lights are off and slams the door in my face and in my arms I'm carrying my 1yr old baby. The shock on my face... I then asked her what is she doing, and boldly she continues to shout at me as she locks the door and walks away like I'm non-existent. Wow I'm just so disgusted by the service. What the nerve she had to even slam the door on me while she can see I have a child in my hands. I told her I'm reporting her to her manager but at this point I feel so angry I just want to cancel my contract with CSS SECURITY.