7 Months ago the same thing happened, no one really answered me on this matter. But after I complained about loosing those cards, they reappeared!
But They made me have to earn them again?? Now I'm on 448 and I got an update. And my free deck backs weren't there anymore? I want those back I earned them 2Xs!! Can you please put them back!! Masha 
russianl@hotmail.com
