As many people are having some problems with getting the rewards, I made this step-by-step guide for you to check it, if you missed any of the steps, there is the reason of the problem.
On Webzen webapage / e-mail
*The event started on Feb, 12th.
All new chars, accounts and invitations had to be made / sent from that date onwards.
*The recruiter (the person that invited) had to log in on his / her Wz account to send the invitations to the friends (those friend's mails had not to be registered on Wz) using this invitation form:
*The recruitee (the friend that received the e-mail), got this announcement:
*Once the friend got the e-mail, s/he has to create an account on Webzen, confirm the e-mail sent by Webzen when creating the account and log in to his brand-new account.
*After having his /her own account, the friend had to complete this form (on the event page) with the details requiered (the recruiter e-mail address):
The recrutee (friend) account had to be 100% new to the Webzen webpage.
*The recruiter had to be lv 50+
*The recruiter or recrutee had to add the other onto the friend list (the normal one). The high lv friend had to invite the friend onto the buddy system friend list via NPC event.
*The low lv had to do, complete and collect all buddy system quests rewards up to lv 70 quest before on until the date the event ended, Feb. 9th.