They said they will give deposit back at Sep 17th.
From that time it is available to get back, then they will check things and send in on mail.
I don't think that is safe way.
Do they give a notification that they sending $400 on mail???
Then after I get the check can I just bring it to bank?
You'll get a check mailed to the address on the account. And yes you can just take it to your bank. It's a check nothing special about it.