VISA card protection

He should immediately contact the card-issuing bank and initiate a dispute for the charge.
The company (here: travel agency) then will have to prove that the bought goods or services were delivered. If not, they must refund it (which can take a few months).
But if insolvent, they might be unable to do so and the debt will just become part of the bancruptcy estate, which means after a very long wait (years!) he might get a small portion of it back, if any.
To clarify the details and best course of action, he should consult a lawyer with the contract and all the paperwork he got.

Thanks for the reply.....but paying Lawyers is likely to result in a bill greater than the €884 paid!   The issuing bank has been contacted but no reply.   Again, in the UK in these circumstances the issuing bank would have to re-credit the account immediately as they are jointly liable under Consumer Credit Act s75.

Is there such protection in Germany?

He needs to contact the card-issuing bank and/or a lawyer to find out what the legal situation is.
Having a well-meaning friends ask others on an Internet forum will probably not help, I am afraid.

As far as I understand the situation, he paid and did not receive the goods or services, so he is entitled to get the money back (plus potentially additional expenses and damages). The two ways to achieve that are a chargeback through the bank, and the legal way through a lawyer.
But if the agency is insolvent, nobody else will pick up the issue and give your friend the money (why would they???).