Confirming Location problem

Hello, I received a letter from Booking.com with unique code, but when i am trying to enter this code its showing me error. Actually now i see its showing i tried too many times but before it said there is some error occured. My code is ***. Do you have any ideas what to do, and how can i confirm my location please? Error after entering code 727520 which i received in your letter 

M Adamopoulou

Hi! Miki and welcome to the Partner Community.

Sorry to hear about your verification troubles.

Maybe you should call your local booking.com office and ask them to guide you.

Wish you well.