Well, Boobers, if it is a Memorex, you call the toll-free number, answer a few questions, and they send you a replacement.
Luckily, some name brand companies, like Memorex, for example, don't have quite the same rules as, say, a court of law. Apparently, they give you the benefit of the doubt. Sometimes, it pays to deal with a company who has a reasonably solid U.S. presence and a customer service staff.
And yes, seeing as you asked, I have had to get two replacement discs from Memorex, they were DVD-RW and just would not burn in my Toshiba SDR-5002. They didn't make me "prove" anything, but I suppose that the fact that I did not make coasters out of them would have been easy to prove; they had no information written to them.
I can't say for certain how much the postage would cost both ways, and I really don't care. They did not want the defective disks back, and they did not charge me for postage for the replacements.
It's a shame you've never had a bad Ritek disk replaced. I guess that means I can't pepper you with questions about exactly how you did it, what proof you submitted, and what the shipping costs were.
Personally, I have stacks of Ritek coasters, and there is no Ritek U.S. office to phone for free replacements that I know of. Still, I don't crap on every Ritek thread, because I am sure that they work well for many other folks with different burners.
Before you spout off about people who "don't know what "name brand" means...", I would suggest a spell checker. Daewoo is a brand name. Dawoo is not.
If you have any other questions, please send me a private message. This thread is starting to drift off topic just a bit.