try someone back again
To attempt to visit or contact some person or location following a failed previous attempt. A noun or pronoun can be used between "try" and "back," but only when referring to a phone call. Professor Smith has actually gone home for the day, but you can try back again tomorrow. No message, I'll just try him back later.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
try someone back (again)
tv. to call someone back on the telephone (again) later. I’ll try her back later.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.