There are a number of reasons for a warped disc, not really a manufacturing fault unless you can demonstrate the wheel, disc or brake pads have been installed incorrectly when it was new. whichever the actual reason for it, it's most likely to be a result of heat. This would mean that regardless of age or miles etc, a warped disc can happen at any time during ownership, certainly within 12K miles on a bike. Has the wheel been out? has it been used on a trackday? do you still have original pads? etc etc. It's all dependant upon whether any external circumstances could have caused it. If nothing like this happened and you can prove it to the dealer they will make a decision based on that, and if they believe you or not. if they do you'll get the warranty claim. I wouldn't hold up much hope of getting anywhere. Normally when the disc has warped due to heat there's some sign of bluing, if there is you've no chance.
I once succeeded with a car but it was hard work, and it was after a main dealer had just installed new discs and pads 2 week earlier.
Just my thoughts and past experiences with things like this. Good luck!