Moderator, Omni, Omni/PR, Omni/Games, FlyerTalk Posting Legend
Join Date: Oct 2004
Location: Between DCA and IAD
Programs: UA 1K MM; Hilton Diamond
Posts: 67,136
Contest the $50 with your credit card if you can't get UA to refund it.
The $50 was to "take over" your ticket issued by an OTA, FWIW. But since the agent claimed he was going to waive it, you should be on solid ground to get it back.