I am in a unqiue situation on this promo. I did receive a message about my credit on the XMB menu last night (April 12-13) around 1-2am EST, but I was currently playing a game and I did not immediately check it. However, 3-4 hours later, perhaps from the lack of sleep, long gaming session, or something else, I completely forgot about it. In this forgetfulness, I accidentally deleted it by deleting all of my received messages (too many old game invites). I don't know what I was thinking, but I know this is entirely my fault.
Anyways, I am hoping the e-mail (not received yet as of 1:20PM EST) will contain the voucher code to redeem it. If not, is there any procedure I can take to fix this problem? From browsing the internet and this forum, I heard messages from the XMB can't be recovered at all.
EDIT: I received the follow-up e-mail (which contained the voucher code) at 2:05PM EST. Thank you for sending out these e-mails for this promotion. Also, thank you Cyb3rfr34k-iso for your advice (I was going to call if the e-mail did not contain the code).