My ex employer is refusing to pay my final paycheck what are my rights?

An employer cannot improperly designate or re-classify employees as independent contractors.  If it is just your paycheck you are looking to collect, contact the Texas Workforce Commission Labor Law Department and file a Payday Act Complaint.  The forms are on their website.  Be sure to mention the reclassification from employee to independent contractor.  If you or others were not paid overtime pay (other than in your final check) after the re-classification you may have claims under the Federal Fair Labor Standards Act as well.  Those can be pursued through the US Department of Labor - Wage & Hour Division or through a private attorney.