ungratefulness

/ʌnˈɡreɪtfəlnəs/
noun
  1. The quality or state of not showing or feeling thanks for something received; lack of gratitude.
    • His ungratefulness for all the help he received surprised everyone.
    • The teacher was hurt by the students' ungratefulness for the extra tutoring sessions.
    • She couldn't understand her friend's ungratefulness after the generous gift.