Discrimination based on retaliation

I work for this company for 3.5 years. Earlier this year, I came to HR and questioned about why I was not being considered for a promotion while everyone else who is less qualify and less seniority is being accepted for a promotion. During my meeting with HR rep. I mentioned that I think I was not being promoted because of my national origin and that I might need to seek help else where if they cannot give me an appropriate reason. One week later after my complain, the company offered me a promotion. I accepted the position with one demand for a merit increas after 6 months on the job. Three weeks on the job, I was harrassed by a verbal reprimand given from my bosses about my management style and a various other ridiculous reasons. I was approved for paid vacation for the month of June and found out while I studied abroad that HR put me on an unpaid leave of absent with no reason. On July 24, I again was harrassed by a verbal reprimand for the fact that my technicians are too loud. On August 29, I was informed that my teams are being mearged with another team and that my position was being eliminated. I was informed that the decision is made based on the business need and not my performance. On September 7, I was place on a Performance Improvement Plan for many other untruth and pretextual reasons. I believe that I have been discriminated against in retaliation for having complained of activity made unlawful. Do I have a valid case?