"Rude and judgemental staff"

I came into the building without a mask because I have an exemption. A receptionist brought a mask over to me and I told them I had an exemption. Minutes later while I was sat in the waiting area I heard them talking with one of the nurses who started staring at me. Then the receptionist said to them “how are you meant to prove an exemption” as though I was lying. The nurse looked at me and tutted. They did not even try to make sure I didn’t hear or see what they were saying. I have never felt so judged and humiliated and couldn’t wait to get out of the clinic altogether.