Hi Jason, it doesn’t matter what link you use as they all have the tracking setup. It may have been if the same browser or IP address was used then the accounts would have been marked as duplicate. VPN/Proxy IP addresses get declined as well. Also there are country restrictions, so if the referral was from a country that isn’t listed on the Accepted countries bit on the referral page then they would go through at 1 JSE.
If it’s none of those things then send us a contact form note with your userID or email address and we will be able to look into it and give you the exact reason.