I have this happen to me. I live in the US (I'm Thai)and didn't pay for my Thai number (you were supposed to keep the number if you want to keep your account) and 2 months ago I was in Thailand I tried to get my account back but I still couldn't because I don't have my thai phone number. also the reason they locked because I had several attempts to unlock the app and if they locked because of that it will be impossible without phone number. And I also can't open the account with that bank again :( . The only way to solve this is to find whoever has my Thai phone now :(