I also felt funny the first time I was there b'coz I never see any visitors. But the Aunty never tell me it's not open to public but told me they are open everyday including PH. She also told me to look around and let her know if I needed anything leh. So I go there quite often and never got booted out but I never go on a Sunday before. Maybe the lady in the office not working so cannot pay for your purchase?