H1B RFE : have all documents except End Client letter

This is about fresh application 2015.

In RFE USCIS has asked folowwing docs

Valid and Signed SOW CRITICAL
Milestone Plans
Purchase Orders
Invoices/Payment Advices
Organizational Chart for the U.S. project showing the associate’s reporting hierarchy
Associate’s Offer Letter
Full U.S. contact information for the associate’s direct supervisor at the U.S. project location
BRM Letter (Business Relationship Manager)

End-Client Confirmation Letter completed and signed by the End-Client

I have all documents except Last one “End-Client Confirmation Letter”. My client is not ready to give letter.

Can anyone tell me the chances of my application approval?

Please HELP

Hi sir. I have received same list for RFE and need your help. Please respond asap