It's easy for items up to 500€. After you receive the package wait a couple of hours (you don't have to wait until the next day) and text them via live chat. Do the usual, tell them you stayed at home all day and waited for the package and were weirded out when it said it was delivered. They're then going to ask you to check with neighbours etc. if anyone collected it for you. Swerve around that and say you have done that already.
This is important: They're gonna ask you if you're okay with them starting an investigation. SAY NO. They can't do so without your consent. Tell them that you or your parents have been Amazon customers for 10 years now, that they also had problems with delivery and after consenting to an investigation lost around 500€ in goods.
The rep then went on and said bla bla we're extremely sorry bla bla and asked where I want my refund. That's it.
DNA IS EASIEST IN THIS CASE