talk to a brick wall

talk to a brick wall (third-person singular simple present talks to a brick wall, present participle talking to a brick wall, simple past and past participle talked to a brick wall)

1. (idiomatic, colloquial) To be completely ignored or disregarded by someone, as if speaking to an inanimate object.

   She never listens -We might as well talk to a brickwall.

• like talking to a brick wall