Regret to say most probably you will have to forget about that wallet already. From what i know wallet is unlock either by password or private key once it is lost there is no way to retrieve it.
That's the sad part of it, nothing else can be done since its a personal data that owners/traders should keep inside a safe notes, lesson should be take by newcomers not to forget backing up all those important matters when opening accounts in any exchange that they'll be going to use, each information have an important role that's why it's been place and required by the site to be well kept.