[Exodeen]

my theory is: this is an item sold by a company and shipped by Amazon (Prime), after you returned the phone was shipped to the seller and they found out it was a fake phone and they did a complaint to Amazon

there are 3 vectors here: the seller, the delivery man and you so there is nothing to worry about

what I personally advise you to do: call your bank to say that you have lost your credit card, they will send you a new one with a new number, Amazon will not be able to charge you and completely ignore their next messages