When you register on a platform and give them your data, they get hold of it. Even if you see it in your dashboard, you can only request for it to be deleted, but it lies in the hands of the company to grant that request or not. It might appear to be deleted from your profile, but they will always have a backup of your data, so it's too late for such. The best could have been never to have used any platform with too much of a bad reputation for privacy or, better still, prepare your mind for whatever comes each time you give out your private data to a third party.