Myself and some others here have reported that the $100 credit has been applied less than 2 weeks after purchase. I know of at least one person who then got the $50 credit a few days later (he ordered a few days earlier than me; I'm still waiting for the $50). The promo on the website says:
- You must be approved for the card by 06/30/2009.
- The purchase must be made by 09/14/09
I've attached screenshots of this earlier in this thread. I would think that with those shots you'd be able to get the deal even if some rep thinks it's expired.
Of course, I'm not from Sony so use my opinions at your own risk.