Not returned; unrequited; not reciprocated.(adjective)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "unreturned" in a sentence
"Wouldn't any normal boy be thrilled to find his call unreturned?"
"Every application that goes unanswered and every phone call unreturned feels like a personal rejection."
"A lawyer I interviewed with in February just emailed me back (after my attempted handwritten thank-you note, two emails and two phone calls unreturned within 1 month of the interview) saying that he couldn't hire anyone now (the "now" itself being quite humorous)."