Karen I agree with Ant's mom, your response is correct.
I tend to have a problem being too sympathic to my employees because I have been there done that, so with his actions I agree with you that he doesn't seem sincere with your son.
I would scout other jobs doing the same type of manager work and just share what they offer in pay and benefits.
Sometimes seeing the print and being able to compare it to what he makes now will help him see what is going on with his boss.
You never know the reason when they stick it out in an unfair workplace.
Fear of failure maybe? He is comfortable where he is and knows he can do the work. Maybe he fears if he leaves he won't find another place he can feel the same way?
Just throwing out thoughts, you never know.
I hope you can get him to see what is going on, there are lots
of employers just like his in the world ~ if they think they can get by with unfair pay they will continue because it means more money in their pocket!
But there are great ones out there too!