(I've moved this to Other Asian.)

Yikes, that's harsh.

Here's what happened to me with Vietnam Airlines.

We were to board an internal Vietnam Airlines flight about a year ago. We were asked for our credit card. I had used my Sapphire card, but it had been slammed and replaced. I hadn't thought to save the old card. Vietnam Airlines wouldn't accept the replacement card. We were forced to buy a new ticket. We did so for the same flight/airline. Vietnam Airlines gave us a form to fill out and apply for a refund once home. It was essential that I have the original credit card number in order to get the refund.

Did Sri Lankan Airlines give you any instructions on how to get a refund? If not, was it a refundable ticket?

I now put a sticky in a trip file telling me what credit card I used for the bookings in order to bring that cc on the trip.