Membership fee invoice uploaded in may as b2c instead of b2b

The invoices of Registered Dealers are uploaded as Unregistered Dealers since our member does not provide its GST and we issued an invoice as an unregistered dealer, now the member is not making payment and asking to provide them revised invoice of current date as well as to mention their GST no. on the invoice. Please suggest since we have filed the return of May 2018 and we have no option to revise the return. Please guide with a possible solution.