Coworkers lost it becuase i stopped buying him food?

I have coworkers and we all got different shifts. Sometimes I come into store on thier shift. When I do they ask me buy them things. Most of the coworkers give me money but one of them usually expects you to just give them stuff. Which I do sometimes but I don't always have the money or food and sometimes I just have whatever meal prep is in my fridge. Well the other site I said I couldn't and they kicked me out of the store and said I not allowed shop at that store when they on shift anymore. Which I just shocked since I didn't think saying no would have them flip the fuck out.