Did you participate in the one in January or the newer one in May?
Mine was for the one that ended may 10th.
I did the one that ended on Feb. 28th 2013, and I just checked my email I got when I received my voucher and it was on April 16th. So for me it was 6 weeks, but I remember some getting there's later.
To add to that. I live in NA, and I seem to remember someone that lived in Canada saying that they weren't able to redeem. They were going to call Sony support, but I don't know what happened with that. That may be why Juan didn't get his, as I think he lives outside NA. Don't quote me on that. Just what I think was said, and I can't look it up since I don't have my recent posts available to me anymore.
Hope that helps.
Edit: Here's my thread. Did a search. I just had to remember the key words used.