Man I've been going in circles with Support this week trying to get my issue fixed. I'm right there with you. All I keep getting from "support" is the same busted line that the Referral Program is automatic and won't work if it's been installed on a device before... but my issue is clearly a backend error that needs higher level support. 

About a year ago I had a friend who used my first referral link, he played about 2 months got level 45ish and then quit. He isn't coming back; ever. Which is fine, so I removed his linked in order to open the spot for another use but it's broken. I've had several friends try to install the game, I've watched them install it on PC, iPhone and we even went as far to pick up a cheap Fire Tablet to install the game fresh with the link and no matter what we've tried that top link WILL NOT sync or show a new linked account. 

The funny thing is that link shows the prior rewards grayed out from when the first friend gained those levels, all the squares except for the new level 10 champ fragments and the level 50 reward that my friend never reached. So, basically until Plarium cares enough to escalate this issue I'll never be able to pick up either of the new Referral Champs because that first link is fully borked.