Why do you only trust convention sites?
Doing research is very important or looking at feedback on this forum. I am sure they will give you the best news, 3.99btc is a big number why you just believe it.
He must have his own reason for that, giving little suggestion is better than just blaming him for his mistake.
This was the response from
https://instaswap.io/We are constantly in talks with the binance and the police to solve this
issue. Once we have more news we will update you.
Err... how is Binance associated with this problem?
You should be fine with the KYC process as it is a basic requirement to solve this kind of problem, you'll then need to prove wallet ownership and many more but it's gonna be worth for your nearly 35k USD.
While solving the problem, I suggest you to create or move this thread to scam accusation section so many people can help you to solve this case.