Can someone please help me 
I told him just to send the 600 euro back to the wallet where it came from but now he does not answer anymore
Daniel will surely have given you a reason why he will only give you the mail address after 14 days, right? Without knowing the exact reason, I assume he wants to prevent users from being scammed (you could claim that the account XYZ belongs to you and you would like to have the mail address). I told him just to send the 600 euro back to the wallet where it came from but now he does not answer anymore
I would in your place just wait the 14 days, Daniel definitely does not intend to cheat you but simply wants to protect his user base.