As others said I've also deleted all my apps from heroku. I was really scared, a bill of $700 out of nowhere, are you kidding??? And not even sending an e-mail

As others said I've also deleted all my apps from heroku. I was really scared, a bill of $700 out of nowhere, are you kidding??? And not even sending an e-mail right after when they've discovered the problem! I got in touch with their support and they took THREE HOURS to answer why I had to pay $700 for dynos I didn't use.