My experience with Bunq. My bank is not cryptofriendly so I had to use something in a middle to topup Binance with fiat. I have sent 100 and 500 eur instantly. After I sent 5000 euro and my account was blocked. Normally bank should have asked for documents to prove that funds are coming from the legal source. Not the case with Bunq. Not sure if they ever will refund my 5000 euro.
Perfect, if you wanted to see them freezing your account. 5 000€ is exactly what was needed

On a serious note, you can be sure they will refund the full amount because it is mandatory. They have no right to keep the funds, even if you don't provide a document explaining the source of the funds. It's like this with any banks (at least in Europe)
Now the next step, since your account is dead, they're supposed to contact you to ask for the IBAN from another bank to send you your balance before closing your account.
It's something that can easily take 30 days
What they actually did.. they refunded my last payment to them with description "Refund because of closed bunq account". But the refund amount was 5 euro instead of 5000 euro. I was trying to get a purpose of this payment several times, no results.. Also finally told me "investigation" may take few months.