Still haven't received my winnings after 3 weeks.

I put in a lot of money at this casino and finally won and requested a withdrawal of $500.00. This was on October 19th, 2017 and now it is November 7th, 3 weeks later and still no funds in my account. 3 times they told me they have processed this and that it is out of their hands and that it is a third party that is the problem. The third party is Instadebit. I have been using Instadebit over the last 3 weeks with no problems at all. 3 weeks wait time in my opinion is beyond unacceptable. How much longer do I have to wait?