Theres not much anyone can do now but I would never have sent him to that lender in the first place. I would make sure I send him to a lender that is ok with apartments under 50sqm. (CBA is one of them). Its a matter of knowing the lenders policies. We have to learn up to 30. The NAB manager only had to learn one and he still screwed it up. That's what you get when you go direct to a bank. You get rubbish service.
