Palm Tree,
I'll start by saying our hiring process certainly has room for improvement...without a doubt.
By your resume alone you are extremely well qualified. But UPS doesn't hire just off resumes. You had 3 face to face interactions with HR and they made the decision to take a pass on a well qualified applicant; why? I would look as objectively as you can at those previous face to face interactions because that is where the problem lies. Don't be fooled by the relaxed environment. Those are on the spot interviews and if you don't get past them you will never get a call. Whether you realized it or not somewhere that 10 min discussion went off the rails. If you can figure that part out and try again I think you will get much better results.
Best of luck to you.