You won 4 holes, i.e. the game was 100 crs per hole.
WGT took 150 crs rake from you - BTW, it woulda been 75 for a 99 crs challenge.
The numbers:
Ante -900
Fee -150
Win +400
Balance -300
Refund (unknown because the other holes' results are unknown,
from the above: -900 - 150 + 400 + R = -300)
From your description, the refund was 350, equalling 3.5 unclaimed skins. How on earth did you get that result???
You better look into your account to see the correct numbers ;)