Roobet is one of the most reputable gambling site today and I'm sure they can answer all your queries so better to communicate with them since you're dealing with a huge money and we all know that gambling can be a good place to spend the money from a stolen funds so you cannot blame Roobet from doing this.
Though its not fair to permanently banned you without defending yourself, they should here your side and if they asked you to provide KYC and proof of income, maybe you can comply with it so you can get your money back and leave this site.
I have sended my KYC full... My acount have unlocked for some days, and after that blocked again.
What about source of income? Or proof of transactions?
Did they ask for any details or what? I don’t much about Roobet terms and conditions but for me they must explain everything to you since this is not an east money. Can I ask what happen to your friends account after spending that much of money? Is he banned as well?