Philippa,

I certainly understand if an interaction like that felt uncomfortable to you, you have every right to expect to be treated like, and addressed as a woman, even if someone read you. Some people are just not very sensitive.

But choosing to see this from a different perspective, by not getting upset in a situation like that, any of us who are either transitioned like you, or just out crossdressed and presenting fully as a woman, are really being ambassadors for the entire T community, and I want to believe that even in a situation like that, our positive attitude and smiles will help such people better accept the next trans person they come across.
Getting offended or upset will likely not help much anyway, so we might as well make it a win.

Hugs
Suzie