Buddy Codes were sent out in Aug of last year in an email. Many ISPs mid-directed those emails into spam folders. If you don't have an email from Visionary Realms from back at that time in either your inbox or your spam folder, then you need to put in a ticket to Support asking them to resend the email with your buddy code. Make sure to tell them the email address you used to make your pledge if you use a different one to put in the ticket.
Also be sure to read the instructions carefully that come in the email. Many people didn't and had difficulty making their game account and logging in.