As someone else said, if you're in Europe you can send a subject access request after sending the deletion request. That will tell you what data they still hav

As someone else said, if you're in Europe you can send a subject access request after sending the deletion request. That will tell you what data they still have about you. You can't _know_ they've deleted everything if the subject access request comes back empty, but it puts then in the position of having to actively break the law to lie about whether they've deleted your data.