Sorry to laugh, but gold balls at $100 (for a player named BallJar, too) is just too good... I'm sure this can be resolved; you could dispute the charge (as a mistake) with your credit-card issuer, but WGT will probably oblige you from their end as well. It's best to send a direct email to members@worldgolftour.com.
As to me, I ignored the promotion, because I'd only find it attractive if they gave out the best-quality balls (GI-SD) as a bonus, rather than GI2-S balls, although those are excellent as well.