I worked on a average of 55hrs. Per week and only got paid for 40hrs. (on salary). Can anything be done?

The hours you, as a salaried employee, worked over your 40 hrs. apparently are not considered overtime. Check with HR or your work contract. If you are considered an hourly employee, then you have a beef, especially if the boss or your supervisor approved your extra time put in.

No, salary is just that a amount of money you get for working, it is not normally based on any secific number of hours.

If you are working for too low a salary that is another issue.

A person on salary have to work any number of hours their company asks

I know almost no salary people that work less than 50 to 60 hours a week every week