Sorry to hear that your speakers are in rough shape! Fortunately, the 3-year/36,000-mile basic warranty should cover audio speakers and other audio components, provided the damage is due to a manufacturer defect.
That said, proving that the damage is due to a defect and not listening to music too loudly may be hard to figure out. Nevertheless, schedule an appointment with your dealer and see what they say. In a worst-case scenario, they simply refuse the claim and you’re right back where you were.
Replacing a single speaker can cost anywhere from $150 to $500+ depending on the quality of the speaker and whether you do the repair yourself.