There are a few possibilities of why referral points may not be registering or registering incorrectly:
1.) If you're currently testing your campaign, referral points are not registered if it's under the same IP address. This is to prevent cheating. If you want to test your campaign, we recommend downloading the Opera browser and using the built-in VPN feature and testing it that way.
2.) The referrals only count if the user actually gets someone to sign up, the points don't come from just sharing. So your contestants must share and then have one of their friends sign up for it to count.