Hi @Aloïs ZIMMERMANN-ROSENTHAL
1) Please consult the FAQ for reasons to this:
https://azure.microsoft.com/en-ca/free/free-account-faq/
2) It may be due to you having another Azure account. Please ensure that this is your first Azure Free acount:
3) If you have any questions you can contact Azure Sales:
https://azure.microsoft.com/en-ca/contact/
If this is helpful please accept answer.