Refund of balance amount in electronic ledger

Sir,

We do have both local and Export sales. We export goods under LUT without paying IGST.

After claiming monthly refund of accumulated ITC on Export (as per formula basis) even there remains an amount in the Electronic Credit ledger which is going accumulated every month and cannot be adjusted with further sales as our Input is high.

Now, whats the process of getting refund on the balance amount left in Electronic Credit ledger. 

Please clarify.