Which Immigration office is he with?
He needs to understand that he needs to show 12x monthly transfers of 65,000 Baht. Depending on which office he reports to bank statements and a bank letter may not be enough.
In my case with Kasikorn bank, and Jomtien Immigration, I had to get a special certificate from Kasikorn's office in Pattaya Klang. I had already highlighted each monthly transfer on the 12 month's bank statements - and supplied the corresponding 12 WISE pdf's for each transfer.