brush-off
 /ˈbrʌʃˌɑːf/  noun  
  the brush-off
    informal   : rude treatment or behavior by someone who is not interested at all in what another person wants or asks for
    I wanted to ask him about his decision but he gave me the brush-off.
    I got the brush-off when I asked her for help.
    — see also brush off at brush, 2