New API/site switchover invalidated giftcodes that were redeemed onto Mojang accounts

Mojang Studios Note

If you have redeemed a code on a Mojang account and never finished creating your Minecraft profile, you will have to contact Customer Support. Profile creations for Mojang accounts are no longer being offered, only for Microsoft accounts.

I have for quite a long time had a Mojang account with a giftcode redeemed onto it without actually having claimed any profile name on the account, as I've been unsure what to name it.
This was possible by simply entering a valid giftcode on https://account.mojang.com/redeem while being signed in to your account, and then immediately closing out of it without choosing any profile name.
You were then prompted with a notice every time you logged into your account on account.mojang.com stating that you had an uncreated profile on your account, and whenever you had decided on your profile name you could just click on the link in the notice and create your Minecraft account with that profile name.

On December 1st this prompt, along with many other features (including the create profile page that the notice linked to) was removed from account.mojang.com, due to what I assume was related to the update on minecraft.net which made new users sign up with Microsoft accounts instead of Mojang accounts.

As I assumed you just moved the create profile page over to minecraft.net I started looking over there for it, and after a while I stumbled across this page https://www.minecraft.net/en-us/set-profile-name , which seemed to be the new equivalent of the old create profile page on account.mojang.com.
When I went to create my profile I was, to my suprise, met by the message "Something went wrong! Try again" however, as shown here:
https://gyazo.com/569b3e1f5fa4c275376b51ba9221dd76

I had heard several other people were using this page just fine with their newly created Microsoft accounts, so I came to the conclusion that I must be getting this error only because I'm trying to create a profile on a Mojang account instead of a Microsoft account, as I'm sure my redeemed giftcode is completely valid.

To make sure you hadn't just reset the account bindings of these giftcodes I tried to redeem my giftcode on a new Microsoft account instead, but I was unable to do this as it said that the giftcode had already been redeemed.

I don't know if you've invalidated these redeemed giftcodes completely or if you're just not allowing Mojang accounts to use this new create profile page, but this essentially renders my giftcode useless, and this is a very serious issue as I, along with I suppose many others, have spent money on these giftcodes that we now can't use to create our Minecraft profiles that we paid for.

I hope you understand what I mean so that this can be reverted or fixed in some way as soon as possible.