Merchandise Issue

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?

Greetings fellow Eorzean!

Based on the information provided, the issue might be better handled by the Square Enix Support Center team. To assist, we have gone ahead and opened a support ticket for you. The ticket number has been sent to the email associated to your Square Enix ID.

This thread will be moved to ‘Support Center Ticket Created’.

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