This is broken

I bought a new Sony Cyber-shot DSC-W55 camera this week at Wal-mart. I installed the software and ten used the web link to go through the registration process. When I completed, I was notified of a 15% coupon on all accessories because I had registered the product. This is appealing. I wanted to get another battery for it. Maybe the 15% would help defer the cost of buying it directly? Yet after going through the order screen, inputting the coupon code as instructed, I was then told this coupon doesn't qualify for the purchase selected. What a waste of time! Note: screen shot images modified only to remove personal data.