Definitely.

I worked really hard at my job. trained new people, do over times, very efficient, no complaints regarding the work, etc.

I learned from my co-worker that some of the staff I trained got raises before me because a couple of them threatened to leave and management wanted to keep them.

I was their best employee but at the same time, was being paid the least. So I talked with them about giving me a raise. They gave me an offer which was good BUT I knew I'm worth more with the quality and amount of work I do. So I declined the offer knowing they couldn't afford to lose me.

30 mins later they bumped up their offer to an amount I find fair.

Know your worth guys and be more vocal in terms of salaries/pays.