How can I find whether my refund data has been successfully transmitted by GSTN to customs or not?

GSTN is reportedly working on a feedback/message system so as to inform the exporters about such failed validations. At present, the Customs system does not have any information about the reasons for which validation at GSTN has failed. However, for all those records which have been successfully transmitted to the Customs system, the report can be generated at the end of field officers. Even the exporter has the option to check the GST validation status for his shipping bills in his ICEGATE website log-in for all records transmitted by GSTN.