What is the best way to design a ‘debt’ screen

So I've been searching for this, but I think Google thinks I want to know about 'UX debt'.

The thing is, I've been assigned to design a new screen for when our customer hasn't paid for the service. He can't log in anymore, and the screen is telling him to pay for the service, or else his account will be locked.
I know how complicated this can be, I want him to pay, and I don't want to hurt his feelings.

So, I needed some example-screens and tips for this type of screen. I couldn't find any on google. Can you help me?