Not allowed to use my own hand sanitizer

I went to Identity and Truworths in Thavhani mall upon entering the store I showed them I have my own sanitizer and I sanitized my hands. Their security jumped in and told me I have to use their sanitizer otherwise I will not be allowed entry. I have a very sensitive skin and I prefer using my own sanitizer but I was treated like I didn't want to sanitize and all I wanted was to be allowed to use my own sanitizer. They called the manager at Identity and she said I can go complain since it's the head office policy. I have been to many Truworths and Identity stores I have never been humiliated like this. Does this policy only apply to certain stores and why is that.