FWIW, if this was somewhat recent, Gamers Nexus recently did a segment [1] on ASUS' warranty support and practices, and they say that they are making some improvements to the way warranty support is being handled. They claim that they retroactively reviewed, or will review, warranty cases for issues such as what you outlined like shipping being charged, high RMA fees, and so forth.
[1] https://www.youtube.com/watch?v=Z0ZoCYXmF0Q