However, it is possible that the automation of payments and security rules simply do not allow using the manual mode in this case.
By the way, I would really like to know this from those forum users who have encountered a similar situation.
I see the fund in this case is not small and the user can afford to pay support fee if Roobet team requires it for fund recovery. The bottom line is there are many other things to consider on Roobet side that can make them want to support or don't want to support the user. If in ToS and Help page, they have no mention about fund recovery, the user will only have a last hope, contact support for escalating investigation and support.
This is really the problem if they commit mistake by sending funds on wrong network since they provably get an issue for recovering it. I guess what need to do is to send again some message and ask for possible solution and he should state that his willing to pay recovery fees which is common on exchange as I remember and maybe this is applicable on casinos to. And maybe they could help if they see the user got an issue like this is willing to cooperate and wait for how long this issue will be solve.
It really awful to encounter this issue that's why its good to do double check before sending funds to other platform so people could avoid this kind of issue.
Of course, you need to write to the support again and then inform here about their response. After all, the amount is really quite large.