) but if transferwise have done this for you and they have had there fees then they should help. For about 100bt kasikorn can provide a letter. You Only need to bs a little bit with them and tell them you need a letter for a visa for proof of money in account. After all immigration should accept the letter as it will just be your balance and it won't say where it come from.
I seen money (a lot less than you have) been taken off a firang cos he couldn't prove where it come from. Like one post says get a thai bank and transfer to your thai bank. A lot safer.
So easy to open an account but if you have any difficulty then there are firms what can do this for you for around 2k baht
It's double that in Pattaya so think yourself lucky..
Admittedly if you do it on your own then it is small money. But your retired ffs so chill out and relax and try spending your retirement fund on somebody who can do it for ya cheaply and stop your whingeing!! You sound like my mother bless her!!