I need help with a merchandise that came with an in-game item code, and the code is not working, it says that it is invalid.
I have contacted both

https://store.eu.square-enix-games.com/en_GB/
and
https://support.eu.square-enix.com/

And in the end I am told to contact my retailer, but i bought the product from the https://store.eu.square-enix-games.com/en_GB/ , and they told me that they can not help me with replacing the code and that i should contact https://support.eu.square-enix.com/ , and these told me to contact my retailer...

Who's my retailer?
Who should I contact?
What is there to be done?