Can an employer in Florida change you from salary to hourly without notice?

First some background so nothing can be assumed and you have the correct story to gauge your response, any reference to actual Florida laws or statutes would be much appreciated.

My employment with "Company BS" began on Feb 14th, when I showed up for my first day, for training, I was told by the owner he couldn't offer me paid training and I would have to do it on my own dime, this was news to me but accepted it as a friend of the family helped me land the position. On Wednesday, February 16th started my paid employment, by Friday, February 18th the decision had been made to put me in a Operations Management position on salary for 50 hours per week.

To shorten the story, over the next several days and realizing the owner expected me to be connected 24/7 and work well beyond 50 hours a week but still only get paid for the 50 since it was a "salary" position I decided to confront him in which he said we needed to go over separate ways. My employment ended officially on Monday, February 28th. During the period from the 16th through the 28th I worked everyday in some capacity whether on-site, in office, or via cell phone totaling well over 100 hours.

As of today, March 17th I still have not received any pay. Finally today, after trying to make contact with the owner for while I receive an email in which he states: "your check was mailed today due to my adjustments to your hours actually worked vs salary..."

I can only assume from this statement that he is planning on paying far less than what I truly worked since in his opinion working from the road or on the cell phone doesn't count even though your conducting company business, and not to mention he is taking it upon himself to change me from salary to hourly. I sent back an email stating that he must being paying me more than my salary would be then since I worked over what the salary hours require me to.

This guy is being shady and trying to find ways to nickle and dime employees since I have heard other complaints and our work relationship did not end on a good note, however, I'm still owed what I did in the time I was there.

Where can I go to report this if anywhere and what are the laws governing this activity?