Gstr 4 problem

I was to file GSTR 4 for quarter July-Sept. on 07-12-2017 My tax liability is 3030 which I have deposited in Elect Cash Ledger. By mistake I have clicked on Submit Button without filing return details (like Supply details and tax liability). Now it is showing Status: Submitted. and Tax liability is showing Nil. Nowhere it has asked for the details of inward and outward supply. What should I do now to avoid penalty and interest?? How can i pay tax now by using balance in elec cash ledger? as return is submitted now And one more thing is now when I am clicking on File return button it is showing Error: System Failure. Please Help...