Theres been a lot of troubles with the scb app recently, apparently affecting thais too... have you been in Thailand this year? If not, I guess you didnt get the sms from your bank telling you to go update your info (to sim-operator where they take picture and input your info). If your phone number is not same as in bank info, then you need to visit the bank too
What detailed information they asked from you, that they already didnt know? If you're as suspicious as this anonymous post, they had a reason to be too :)