No, I haven't sent KYC documents. They refuse to explain why are they asking them. What am I going to prove them with documents?
They think that I was coin mixing, but why would I "mix" Monero? They lie or they have no clue how Monero works. Who is mixing Monero through dice and what would be the point of that?
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They have held your withdrawal as a suspicious activity of mixing Monero. Does it make any sense there!! Monero network is fully secured and it is well known as untraceable crypto. Monero doesn't need any mixer. It would be better if you can provide the proof/screenshot of your deposits, withdrawal request and your conversation with support in your post.
If they have asked the KYC documents for any other reason then you have to go through the process to receive your withdrawal. It is written in their
Terms5.1 DuckDice reserves the right, at any time, to ask for any KYC/AML documentation it deems necessary to determine the identity and location of a User. DuckDice reserves the right to restrict service and payment until identity is sufficiently determined.