JetAirways (India) Ltd — invoice with gst breakup for my travel in jetairways (india) ltd

I had travelled in jet airways from chennai to new delhi on 3/apr/18 by 9w736 and returned on 07/apr/18 by 9w841 (Reference pnr no brguia). As my trip is official, i submitted my invoice for re-reimbursement but i was asked to submit invoice with gst breakup. So i approached jet airways through emails and phone to send me invoice with gst breakup, after several attempts in month of april 2018, they emailed me that they would send invoice with gst breakup in the 1st week of may 18 as i quote from their email "our invoicing system is still under the process o[censored]ploading the gst invoices.in view of the airline industry complexities, the process is taking longer than anticipated and we do regret the delay. This is to update you that the gst invoices will be issued by 01st week of may 2018." but still i pursued through emails and phones but till date i haven't received any communication or invoice with gst breakup from their end.