I'm somewhat reverse of you. I kept married name on passport for family name and bank account in pre marriage name. Recently gor retirement visa. I asked passport office (Ireland) to add my pre marriage name as an 'observation' so I now have both names recorded. I opened bank account in married name in Thailand and transferred funds from Irish bank account in pre marriage name. Now Passport, Thai bank and visa all in married name in Thailand
They possibly want to think it is not a genuine ticket. Maybe send proof of payment. And perhaps the customer support for the airline can also issue a receipt. Or it could be available with your booking confirmation
I was recently in hospital in CM. I sent a copy of my flight ticket which was acceptable. As it was travel insurwnce I think they wanted to check I wasnt already living here when I got the policy.
The hospital were very keen to get paid and thry had a person liasing with insurance. They may know the requurrments if different companies.
I have already transferred to Thai baht account. 1% fee. It'll take a few days. Then I need to transfer to Bangkok Bank. Ho0efully I can get the letters suggrsted by Sarick above. Had hoped I could insert a narrative linking the transactions