Most of my champions have been removed from my account

Prochienne

I haven't played the game for a while and when I logged on I had on 2 star champions and only 5 of them. I used to have 5 stars but now they're all gone. Any idea on how I can get them back?

SummonerNR

Probably logged into a different account.

Had you ever had multiple accounts ?
Was the last time you logged in, from a different device that now ?
Was it from logging in using GooglePlay or PlayCenter, instead of using an actual Kabam ID (or visa versa).