Netflix account? - 2

I'm a student and would like to be able to do netflix and may only do it via direct debit but that does not work, does anyone have any idea why?

What is not?

How old are you and what exactly is not?

I'm 16 and if I want to pay on netflix with direct debit there's always I have to choose another payment method or that there's a mistake but I have looked and entered everything correctly.