First question - are you in the US or Canada?
In the US clutch linings are covered by warranty for the first 3 years or 36,000 miles. I'd start there and have them explain why they think otherwise. Unless they can point to abuse then the problem should be covered if you have simply worn it out. Any other failures such as the TOB could be a warranty item as well - if they pull it apart and claim abuse, ensure there were no problems or unusual wear with throw-out or release bearings, and also that the clutch lining hasn't worn in an odd way (scorching could be explained as abuse, and unless you had previously reported a sticking clutch you are unlikely to get away with it). The big problem is that the dealer can say what they want - for example, a sticking TOB could be caused by the dust created from hard launches. You might simply have to pay up and then make a claim through a small claims court. I'd try a second dealer first, and don't forget to leave a review of your experience on Google!
In Canada the clutch is not covered by warranty unless something has caused premature wear. I have a couple of experiences with this myself, one bad and one good. I reported a hill holder problem with my new 2008 WRX (clutch had to be slipped to avoid stalling because the release timing was out), and when the clutch died after 15,000 miles they called abuse because it had scorch marks on it because of "slipping". After some arguments and a threat of court action we compromised on me paying for the parts but not for the labour.
Needless to say I switched dealers for my 2015 WRX, which developed a sticky TOB problem after a couple of years. Fairly, this dealer said that if they pulled the system apart and found any kind of abuse then I would be on the hook for the work and parts. However, they found a manufacturing flaw with the clutch lining material and therefore replaced the bearings (signs of premature wear) and the clutch lining (not worn) under warranty. So really you need to let them in before they can give you an answer, and then you have to hope they will be honest with you (because they make less on warranty labour).