[quote]I'm trying to get the Dredgen title, and only need to prestige gambit and to get 3 medals of Thrillmonger. I did the "Dark Age Arsenal" today, but for whatever reason I can't get the medals? I got 50 enemy kills last match and still no progress. Is it no longer possible or a bug?[/quote] It's absolutely still possible. I earned the medal in a recent match.
Thrillmonger is 40 kills in a single match without dying, you have to hover over the medal to see the full requirement otherwise you may assume you can accumulate them throughout the match regardless of dying.