無功而返 [无－－－]

Jyutping mou4 gung1 ji4 faan2
Pinyin wú gōng ér fǎn

Definitions (CC-CEDICT)
  1. to return without any achievement (idiom); to go home with one's tail between one's legs
Definitions (Wiktionary)
  1. phrase, idiomatic
    to return without any achievement; to go home with one's tail between one's legs