The casino itself should be the one contacting the game provider if their users experience this issue on their website. It’s very unprofessional for them to just passed you on the 3rd party game provider without doing their part on contacting the provider as you are their customer. Cashdrop should be drop automatically if you win the contest after the tournament ends.
Can you provide here what’s specific tournament you join so that we read the ToS and help you by understanding the full mechanics of this contest. Upload screenshot too that provng that you really win the contest. You can upload screenshot on talkimg.com and paste the image link here.
You're right mate, it's the job of the casino to deal with that. Usually when we complain to the customer support of a 3rd party game provider, they say we will get updates from our casino and not from them... when they bother to accept our query instead of inviting us to contact the customer service of our casino.
They usually explain they don't manage funds and players' balances, only the casino is doing it.