Not sure if this should be in forums or not, haven't seen it posted yet so here goes, play a candy crush like game on the first page of the app you'll see it (60 seconds per game) and get diamonds to redeem for prizes - 150 diamonds each.
Simple enough 1 hour per life up to max of 5.
I average 6-8 diamonds per game & Got 50c Cash back from the prize box yesterday just from playing.
You're guaranteed to win something and there doesn't seem to be a limit on the amount of times you can do it.
averaging 7 diamonds per game, first prize was 50c cashback aswell 😊