[Leonidas76]

Yes the reps have been negligent in responding to your problem, specifically. But it is not uncommon so don´t worry too much about that. I do find it weird they contact you by phone, is French your native language? Although it is common that Apple calls, I did expect them to contact you through e-mail after you didn't pick up the Irish phonecall.

Well if they send evidence about the empty envelope, and it is through e-mail, we can work from there. If it is by phone, simply state you have no idea what they are talking about and that you would like to receive evidence to support their claim through e-mail.

I don't know how the police works in your country either, but I would suggest looking this up and see if they allow for online filings. You are in the process of returning the phone and I would suggest waiting for that process to end. If it fails, you can always do a P/P dispute or CC chargeback