I have a question?
I worked 9am until 4:25pm and the owner of the company says I only get paid until 4:15pm. Shouldn't I have been getting paid until 4:30pm? If he has been doing this all along than I feel like I have been cheated out of a lot of time.

Yes. The federal regulations provide that rounding can be done to the nearest 15 minutes, but it must be the nearest 15-minute interval, not the next highest 15-minutes. UNLESS if you start work early, they also round up the same way.

In other words, the rounding must be consistently applied, regardless whether or not the employee or the employer gets the benefit.

Based on what you've posted, I think you do have a complaint for unpaid wages, which you would file with the state Dept. of Labor.