I booked a BA flight using my companion voucher and amended the return flight from Tokyo to London on 8/2/24. I am now in Japan and flying back in a week on 17/4/24. I still have no ticket number despite trying to sort this out at Heathrow when I took the outbound flight on 20/3/24. I spent 40 minutes on the phone to someone at BA who told me it would be sorted within 7-10 days and I wouldn’t have to call back. It’s still not been done 3 weeks later. I spent an hour on webchat who can’t understand the delay and say I have to call but I have no roaming so this isn’t feasible. Am I safe to just turn up at the airport for the return flight and it will be sorted there?