need to talk your sending bank and confirm where the transfer was sent in detail and ask your bank where the transfer came from? Maybe the miscode is in the BAHNET system.
If the payment came from a BAHNET origin it means the its internally sent inside Thailand from a third party bank, you need to ask your Thai bank to complete a FET form or Foreign Transaction Form, they send to the Third party bank and supply the details of the payments orgin. It cost 300thb and probably takes 2 weeks or so. You should find out from First Direct why its not swift transfer.
If your payment has gone through a third party bank in Bangkok on its way to you you need you need a Foreign Exchange Transaction form your bank fill in the details at thier end but send the form to the third party bank they add thier details like where it came from. It cost about 300thb and takes a few weeks.
I've know a lady. A friend of my wife, we've known her for 10 years or so, she handles DLs, she is in Pattaya, but can do it remotely (I think) its 2,500thb (or it was) so not cheap, but if your stuck i can give you her deatails.
You will likely see any Goolge subscription change to local the local levels. Also if you used Google verification (when you signed up) for other UK financial services they maybe affected. Just think about what you have linked.