For the past 5 matches of ARAM, i didn't receive any reroll points. At first i thought it only works when winning an ARAM. But there were plenty times when i lost and still got the points. I tried what i could on my end. I restarted the client, i repaired the client. Nothing worked. I just won a match where i didn't have any reroll points from the beginning, and i still have no rerolls.