Closing Store Before Stipulated Time

We buy most of our groceries from Checkers Heidelberg and the service at the store is great either than the chattering with fellow workers being the issue that would tick a lot of people of.

What I have been observing over time is that the store closes its doors way before 19:00 or 20:00 on the different days as per their trading hours.

This pass Sunday( 11/02/2018) I got to the store at around 18:53 and when I got to the door, the security guard closes the door on my face. I then asked his as to why has he shut the doors before closing time as per the operating hours and his response was that they are closed as per management's orders.

I then went on to say to him that is wrong and he should open, he then moved away from the doors and disappeared when I took out my phone to take a video.

What I want know from Checkers Heidelberg is, if it is standard practice for Checkers to closed its doors before the communicated time as stipulated on their doors and elsewhere(website).

I am also attaching a video on the day of the incident.