achievement quest bug

Hi 

Actually a month ago I left my league to join another so that i could complete my join a league quest because it was bugged 
But when i rejoined it reduced my quests from 87 to 63 which has made it nearly impossible to complete my achievement quests as even after reaching fc champion in all three i would have 98 and need 2 more which is nearly impossible and so i am not able to complete the achievement quests to claim 20k gems