Hey @robymendoza, welcome to the community!
Since your Spotify account went back to Free, you'll need to update the country to the US following these steps.
Once the country is updated, you'll be able to get the student discount or Premium.
If you're getting any error messages when entering your card details, try clearing your browser's cache and cookies or using an incognito window.
Let me know how it goes.
“Music acts like a magic key, to which the most tightly closed heart opens.”
― Maria Augusta von Trapp