my paycheck was short 28.5 hrs of overtime, when do they have to have that shorted amount paid to me,

An Texas employer must pay its houly employees no less than twice a month on a regular schedule and its salaried employes no less than once per month.   There is no extension of these deadlines for an employer to make up a short check.  It owes it immediately. There are two options for you.  Texas Workforce Commission - Labor Law Department (Payday Act Complaint) or US Department of Labor Wage & Hour Division.