Definitely see if you can get a replacement. It's so new, you might.
To fix it, what Don said is good, but I'd use a plastic welder for sure on the pin so it hopefully fuses... You'd basically be tapping the piece that broke off and the other piece, and running something into the holes between the two to strengthen them, and then you'd really want to fuse ("weld" with plastic welder) that break together. Pins on SW figures are styrene and react to plastic welder.
I'd see if you could put a more rigid type of pin into it than copper or brass if you can though. REALLY thin all thread might work, but I haven't ever seen it that thin. A longer threaded plug from the hardware store would work too, but not too large a diameter, just long... they'll self-tap into plastic even if you get just the right diameter.
Definitely try Hasbro first though. New figure, they should in theory be able to help, but keep in mind they love to go the, "item of equal value" route, so don't buy into that and argue it.