I play arena on phone glaxy a7 with priest 2 win and 2 lose .in this game 5 i win a demon hunter opponent and out game . when i come back i see the arena gift for 3 win with 1 one pack and 2 box = 60 gold .
Did you have a disconnect during matchmaking (while looking for an opponent)? Or maybe you cancelled the search just before it matched you. See this: