While I feel your pain as I too have experienced poor tech support problems in the past with many different kinds of companies, I think that you went a little overboard.
Realize that the folks on the tech support lines likely have nothing more than a basic troubleshooting flow chart for each basic problem you could experience with a faulty device. Now some tech support folks go above and beyond to understand their job whiles others simply "Nod smartly" and follow the pack. The supervisors are hit or miss and some might be the "go-to" folks while others are folks that didn't get a role as the manager in the movie "Office Space".
I think once you got the basic response that you'd have to call on a normal business day, as some tech support shops only do "skeleton crews" with minimal people on the weekends, you should have just gotten the names of the people you talked to and put that in your pocket.
I have done exactly what you have done in the past, being overly persistent bordering on rude (but you weren't you were just frustrated, I understand). It typically resulted in no significant change in service or expediency of resolution.
Do not interpret this as a defense of Asus and your incident. Unfortunately businesses nowadays practice the concept of requiring a diplomatic/political approach in order to get things done instead of simply relying on the age old foundation of Integrity and Excellence. It is by no means an effort to achieve perfection but by understanding that so long as you do not compromise your Integrity and professionalism for political and beuracratic ascension, you will see better results in the future with less stress.