Both Sides On Poor Form

(I work in a department that offers grants and loans. Recently, management has made a decision that applications will only be processed if applications have been completed 100%. Previously we’d let applications through if they hadn’t indicated how they heard about the scheme or indicated if their car was first- or second-hand. While this makes sense, I am currently trapped in limbo with a customer with the following set of emails. Please note that the customer had emailed their application.)

Me: “Unfortunately, we cannot process your application at this time as you have not indicated your preferred email address for correspondence. Please fully complete the application and return this to us to allow us to proceed.”

Customer: “It’s the email address I’m using just now.”

Me: “Unfortunately, we can only accept this information if it is on the application form. We are not able to accept this information in any other way.”

Customer: *attaches incomplete application again* “It’s the email address I’m using just now.”

(Management still wont let me accept it and we’re stuck in a loop. Whose fault is it really?)