Didn't receive my basic champion cube of each level

first of all i was playing aram with lucian then after i finished i leveled up to 14 and it showed to me that i got basic cube that anyone get each level up but when i opened my loot i didn't find it , so i restarted game,begin client repair and nothing happen so its purely Bug so i hope someone help me to fix this bug since support website doesnt work and i wanted to get my Cube back.

Maybe its not a special cube for most of u but for a beginner like me its essential for getting more champion shard and blue essence