It's the whole "allright me darlin, see you've been having a nice day shopping now don't you care about the lesser-spotted Guatemalan dung beetle a lovely lady like you" shite they pull. I've complained to the charities in question before when they started pulling the sexist shite and commenting on my appearance.
Since I got older, more stressed, and more fat I'm less visible to them now but they get nowt more than a "no thank you" from me.
The door-to-door ones ring, then peer through the window and start gurning and waving at you if you ignore the door.