@Yo***
I did mine with Thailand Visa Center - I was picked up at 0800 from my apartment and went to Krung Thai bank . Agent brought my paperwork/ passports etc and the Bank officer will check for my Non O 90 days stamp in the pp. when all is in order , my agent gave them a whole stack of Thai 1000 baht notes . It was machine counted showing 800K . When the passbook was returned to me , I could see a 800k entry credit . And another of a withdrawal of 800k