Costco

I'd been a loyal customer of Costco for the last 17 years. Today I went shopping and didn't wear a mask. The mask mandate was lifted in the Johnson County, KS, where this warehouse is located, starting May 1, 2021. The masks are recommended now but not required. I have a health issue with breathing and struggled this whole time while the masks were mandated: I avoided going shopping most of the time and relied on buying online as much as I could. I am tired of being harassed by people asking me personal questions. According to the HIPAA rules, I am not required to give my personal medical information to anyone, and people should not ask me personal questions like why I don't wear a mask.
The manager of Costco came by to me while I was at the register and asked me to put my mask on. I said "No, thank you. I have a health issue." He next said that I should not come to this warehouse again without a mask, that I am not welcome here and that I need to give my membership card to the customer service for reimbursement. I feel harassed and discriminated against for being disabled. Every time I come food shopping to Costco I leave $500-600 at the register. I don't even mention numerous household items that my family bought though the years and this is the gratitude that I deserved for buying from Costco? I also use pharmacy and buy glasses and contacts. So, because I am disabled and cannot wear a mask am I a bad customer?! I can think of taking my money elsewhere if that's the case. Thank you