I work in a pet supply store. The other day, a customer with a pug came up to me with a harness and asked if I had it in an extra large.
M: I think the biggest that one comes in is a large, let me just double check though.
So I had a look at the size guide tag on the harness. Sure enough, comes in XXS-L. No XL.
M: Yeah, sorry, it doesn't come in XL.
C: Oh, so you have to order it for me?
M: No, I can't order it, sorry. They don't make it in an XL. I can definitely help you find a different harness that will fit your dog though. Have you tried the large? I can help you fit it. I'd be really surprised if it was too small for a pug, it's meant for a larger dog.
C: No, I need the extra large. You ordered it for me before, the one he has is extra large.
M: Yeah, that's actually a different brand and that one has been discontinued, unfortunately.
C: Can you please order the extra large?
M: No, look at the tag here. It only goes up to a large. They don't make an extra large.
C: Can you please order it for me?
M: I'm sorry, I can't order something that doesn't exist. Let me know if there's anything else I can help you with.
And with that I walked away, because I was pretty sure it was never gonna end.