contact official profile. email/dm GD official profile.
be polite even if they are dragging ass.
if in US, sign up for informed delivery -- you can see packages that are in the system headed to your address. International mail may not show up until it hits customs (ICS), but even if they don't have tracking from original post, USPS will provide free tracking once it is in their system. If not in the us, check out your local post's website as they may have something similar?
Anyway, it is not uncommon to have to send a reminder if they have not sent it out or contacted you within a couple months. IT takes a month fo them to sort out the winners and communicate the info. it's not a streamlined process but as long as you hold them accountable , it'll get sent.