Will my cancellation request be accepted by amazon?

I ordered a iphone 4 otterbox case and then about an hour later I realized I didn't need it & then I requested to cancel it. Now I'm wondering if it will be cancelled and will my money be kept? And how long will it take for it to be cancelled?

Go online and look for the status. That should give you your answer. They will also have contact information for inquiries / questions. Go there and ask them.