Why would you think it was free to use the face paint?
It does seem like over re-action from both staff and customers and as always no winners.
IIRC you have to pay to get into the soft play bit already so the OP probably thought that the face painting that they'd already paid for.
We were thinking about a Pub
lunch today anyway and was reminded of the Derby Pool by this thread. Had a great feed - got to recommend the Chicken sharing platter