$100 iPhone credit can’t be used on iTunes

Apple details offer to customers who bought phone before big price cut

Apple Inc. has begun allowing people who bought iPhones before the higher-end model's price was abruptly slashed to apply for a $100 store credit.
The company said the credit would be available for people who bought either the $599 8-gigabyte, iPhone or the $499, 4-gigabyte model before Aug. 22. People who bought the phones more recently are eligible for refunds.
Those early buyers must fill out a form on Apple's Web site to have the retail or online store credit delivered to them electronically.