What do you call someone who cannot be bribed?

Such a person is called dumb or mute. Mute may be preferred, since dumb has also acquired the informal connotation "stupid."

A person who cannot walk is termed disabled.

Ignore them, or say thank you I take that as a compliment then they will freak out but they won't say anything back except you're welcome. Just say "OK." and compliment them. It works! There was this...

see a specialist and find out about a hearing aidUse Relay ... operators type out your conversation so that you don't have to hear it... dial 711 and ask to be transferred to customer service