Treated like a ******** - BAD CUSTOMER SERVICE

I am a regular customer of the Food*****'s Market in Sunward Park Boksburg. By regular, I mean I buy there every other day and spend no less than R400 at a time. I went there to go buy the frozen smoothies they sell, which was low on stock. I buy smoothies for myself and for a friend of mine. So I wanted to take a picture of the different options they had of a new smoothie in a cup, only to be approached by Francois (a floor manager) to tell me I am not allowed to take pictures, and then appointed a man to watch me after he left... I found this to be ridiculous, as Francois didn't even bother to ask why I am taking a picture and if they are able to assist in some way to help me....he just assumed I was taking a pic to maybe cause trouble for the store. They treated me like a ********, which I do not appreciate seeing that I do support that store a great deal. I would really like to know if the store policy is to treat every customer like a ******** and with such disrespect????