If for a long time your relationship with the platform was in order and all your conclusions were approved on a regular basis, then you just have to continue the dialogue.
I don’t think they will decide to pocket your winnings just because it’s a big win. Revenue from such platforms is much higher.
How long have you been playing on this platform? Have you ever withdrawn large sums from there?
The thing is, the said "upper support" demanded a fee before they will allow OP to withdraw his winnings. This is an in your face scamming. Notice the point of the casino representative on the telegram saying that they cannot touch the players money when OP ask them to deduct the fee from his fund and yet threatening the player that they will add it to the jackpot as a donation. It is now a question if that representative from telegram is real support of that Casino, better to ask that person to send all their demands via email then see if they will use the official Jetwin support email.
Everything is correct. Almost everything that is discussed in the telegram is very similar to a fraudulent scheme, after which a given support specialist can disappear in an unknown direction.
The fact that they cannot touch the players' funds is complete nonsense.