When it first came out - I checked my credits, then opened a chest and got 100 credits. It doesn't tell you, but you got them. I haven't played for a while, but just noticed you don't get anything now.
The reason: there are now more frequent chances at bonuses after winning battles and capture the flags, even in losses. It may or may not even out to 33 1/3 credits for every win, but sometimes I get a bonus of 10 extra credits for playing, sometimes a bonus of 500 for a win!
"Faith is the art of holding on to things your reason has once accepted in spite of your changing moods." -- C.S. Lewis