GearBest Free Lucky Bag Email?

I bought a Mii Box from Gearbest a couple months ago and today I receive an email saying:
Thank you so much for your first GearBest order!
Your satisfaction always matters. That's why we're sending you a FREE Lucky Bag.
BUT BE FAST: It's ONE-TIME ONLY and expires in 72 Hours!

Anybody know what this is? There is no link in the email to click through and Support are just useless.