Am i a case of Discr

My former employer is a privately owned convenience store with 5 (going on 6) Gast stations+A tire shop+ A Comfort Inn; all of which have different business licensing but are ultimately the same company whom may require you to be available to work at each location regardless on where your home still is. I worked roughly 126-130hours with in a pay period (2 weeks). In which some of those hours worked are double shifts, and/or shifts with minimal hours as my resting time (4-8hojrs before i am due in for my next working shift.) Because i worked 80hrs;(40hrs a week x2. ) at my home store location, 8hours at another location and 20-30hrs at a 2rd location, i was paid ALL hours worked at 'Straighr Pay' wage. However..... other employees with this company including those staffed at a different 'Home Store Location' got paid O.T pay rate for each hour worked over 8hrz and/or 40hrs a work week no matter which location they worked..... including my significant other who is also employed with this company and i have the pay stubs to prove this discrimination+former coworkers who are willing to verify they have also received said CORRECT amount of O.T hours on their checks. Also, the reports shown to me without clarity on explination for cash shortages are 100% not the reports & paperwork signed by nor turned in by myself- and when i asked my store manager what happen to BOTH close out reports from the same day she did not entirely answer but instead went around my question.... ultimately ending the discussion with me being terminated. Do i have a 'discrimination' case against prev. Employer, or any wrongful termination case against my former employer... oh and one last thing, prev. Store manager is also slandering my name to other associates including doing so infront of my old reg. Customers in which i am told 3 people who stood in line over heard the Store Manager talking to other employees explaining the following on my termination reasons,