their least deposition is 0.00005
you unknowingly deposited 0.0004
You should read more careful and count the zeros.
worth of BTC on the address and it refused to confirm, and BTC has already gone out from your wallet and is yet to confirm in the excahges, so what can you do to revert the BTC to your wallet since the transaction is still pending, so I don't know if its possible to get back your bitcoin since is on pending getting one week the transaction incident occurs.
Are you asking a question about an "excahge", or are you asking about double-spending an unconfirmed transaction?