Ummm, tricky. Banks obviously need to be careful about customer details so I am not surprised that they are unwilling to engage with you. Banks will have fastidious policies with regard to customer details and I think that is correct and appropriate given the potential for fraudulent transactions. I suspect that you cannot force them to deal with you. Writing a letter may be sufficient to get a satisfactory response. Couldn't you write the letter but get your friend to sign it and send it?