So in a nutshell:
You purchased a product from an industry leader, and it began having issues.
You made youtube videos badmouthing the company.
THEN you called customer service, and they responded within 24 hours.
You sent it in for repair. They could not find a problem during a function check, and they sent it back.
Then more social media videos badmouthing a product that failed, even though the company ran a diagnostic test on it, and it worked for them.
Now, after/in spite of all the badmouthing on social media, Surefire again responds and tells you they will make sure you are taken care of, to the point of replacing the light.
Even after you are told that your product will be replaced, you still continue to badmouth them on social media.
Conduct is the best proof of character.
Stay Classy.