Offizieller Kommentar
@Sercan > The retailer should have made you aware if you were purchasing an open box (previously returned) or refurbished (B-stock) unit. If you were under the impression you were buying a brand-new unit, it should certainly have had at least a USB cable and manual included. (I don't believe CDs are provided any more.)
You can contact a Pioneer office in your region to inquire further as it doesn't sound like you'll get far with the retailer if they're not being up-front about the situation. If you are concerned about the product function / reliability, then you should certainly call Pioneer, especially if you were under the impression you were buying a new unit.