As a student i paid already the regular annual subscription. How can i get the student's discount now ?

Hello,

I'm a student from Paris.

In May of this year I bought the regular annual subscription capture one pro ( 219€ ). After that I just found that there is a promotion for students... 

My student status has been verified, and I've got the student code after contact the sheerID verification. I'd like to know how can i get the student's discount now ? Will there be any related refunds will be return ? 

Thanksss !