Can't use Destrier Beret code at all

I am sorry if this is not the proper forum, and ive contacted support by email several times.

Yes i know i can level fast with just trusts, but i still want this beret.

I bought the Ultimate Seekers Edition last night with the specific purpose of using the destrier beret code on a new character i had made. I am unable to use the code because i get this message: "
You cannot add expanded services because either the maximum number of service accounts have been added/registered or there are no service accounts to which the expanded services can be added/registered."
"

i have no other characters on my account at this moment besides this new character. Ive had previous characters on the account who i used past codes on , yet theyve long since been deleted. But that shouldnt cause any trouble should it ?

The code items... are weird. I have never successfully been able to enter the codes either, but I believe you can just go grab your hat and shirt because the codes are automatic now.

I've never bothered to try though since it's just a waste of inventory for me.

Sadly what you suggested did not help me. IT sucks, i dont even really need the ultimate edition code, just thechocobo shirt and the destrier beret.