Amazon hasn't been hacked, really. What is very likely, is that your details were compromised elsewhere, it's common that people use the same email address and password combination on other sites. Be careful when you discard boxes, packing slips or whatever with your email address on, it's quite trivial to use an email address collected this way on a site such as https://haveibeenpwned.com/ - go find what the password has been decrypted as, then try and login to things such as amazon, gmail etc. If you are serious about your online security, consider using something like 1Password or LastPass, these will generate random passwords for you, that you can use on sites so that this type of attack doesn't work. It sucks that the amazon delivery person didn't deliver correctly - but Amazon will absolutely make good on this, if it was them at fault.