"Attitude of staff member"

I've been going to James Lind House for different services. One member of staff makes me dread arriving at the clinic or talking to them for any reason, and they're the one that's there most of the time when I go.

They greet me politely but with no warmth, as if they are following a manual on how to be nice. I'm polite and smiley, I try to be friendly, but they are just cold and act as if they'd rather not talk to anyone all day.

If I arrive early, they get grumpy, telling me - You're here too early! If I need to ask them something, they act as if I'm inconvenient.

One time I was struggling to figure out how to open the door and instead of calmly and politely telling me what I was doing wrong they just shouted - push! Looking very displeased. Another time I accidentally walked across their path because I didn't see them so they had to stop abruptly as to not hit me and I apologised profusely and repeatedly but they just looked at me so disgusted like I'd slapped them or something and left.

It's a pity because the rest of the staff there are beyond wonderful and I've never had issues with anyone. I'm the kind of person that tends to be warm and friendly and get along with everyone, and I thought long and hard before complaining here, but I am in therapy and when you go to therapy and there's someone there all the time looking down on you and making you feel like dirt on her shoes, it's very unhelpful.