Claim settled by ECGC can be considered for incentives under FTP

A claim settled by ECGC can be considered for eligibility of incentives under FTP and drawback but not for service tax refund

We are a Star Export House. We have exported some item to a foreign buyer under two invoices. We have received drawback and service tax refund on these immediately thereafter. The buyer has defaulted on the payments, being bankrupt. ECGC of India has settled the claims @ 80 per cent and 90 per cent. We intend to reverse and return the drawback and service tax refund received by us for these two invoices. Should we reverse and return the entire amount or only the pro rata amount of the bill settled by ECGC? Can the claim settled by ECGC be