Work issues

My bf has been with a company for 3-3 1/2 years now. He works long hours and always comes home stressed and aggitated. A couple of months ago his bosses told him they wanted to raise his pay since he was doing so well and their was a promotion available in his division. He and a handful of his other coworkers got a cost of living raise of $1 a week after this and he thought he was getting the promotion as well. Instead a coworker that had just been out for a week in jail got the promotion and the pay raise. Not too long after their was a higher promotion available that only he and a new worker applied to. They told him he wasn't ready and shortly after promoted him to the same position as the first one he applied to, but for a different division and no pay raise. This division had issues they wanted him to fix and they told him if he did well he would get the higher promotion. He's been working hard on this with coworkers that don't want to work while he's there from 7am to 10pm most days. His bosses just announced today that the same guy who got the first promotion got this one as well. He also found out recently that new hires are only making $.50 less than him and feels really unappreciated. I've been telling him he shouldn't have accepted the promotion without a pay raise, but he doesn't want to try to fight it even though he's very upset by this. He's considering looking for a job elsewhere. I wanted some advise on what he should do in this situation because its very frustrating having his bosses tell him how well he's doing and saying they want to help him but only give promotions to their favorites. Should he stick with this job a little longer to see if it improves or start looking around for something better?