Incomplete unit

I recently upgraded from BlackBerry to Sony on my Vodacom contract. After a few weeks now I have picked up an issue with the phone. Returned it to Vodacom, to be told after a month of no feedback, that is physical damage on the phone and the warranty has been voided. Cost to repair to me R1180. Now it's been revealed that the unit does not have the IMEI sticker on the device, as per Sony standard. My question now is, have I been sold a defective device from the start? And that the\physical damage"claim is Sony's way of covering the defective unit? This was all after the unit was booked in without any visible physical damage. So frustrating!!!"""