When I signed up with a similar promo, it took about 24 hours until the extra bonus data was added to my account. I would say be patient for a day or two, and if the bonus is not added, then contact a Mod and they will help you out.
I have seen a similar issue where the self-serve account was not actually created, despite the number and sim card being active and working. It was a simple fix by creating a new account and linking it to the phone number you have signed up with.
