Unlocked genuine IPhone 3GS with 8 months warranty remaining !

I am selling my 4 month old Unlocked IPhone 3gs as I now have a IPhone 4s, so I no longer need it. There are many fake units being sold on gumtree so I have the receipt with the serial number to prove it is genuine. The phone is classed as a B category and on the 19th September last year I paid £305 for it from CEX. I have taken a photo of the receipt which shows the price and date of purchase and the buyer will take on the 1 years warranty which came with the IPhone. If any problems are found with the Phone CEX based in Merry Hill will replace it for the same unit free of charge. please feel free to call CEX to confirm this. I would like to get £180 for it and although there are cheaper iPhones on Gumtree - none of the ones I looked at come with a warranty and proof that it is a real IPhone 3gs. Do not leave a voice mail...... Please call or text Simon on 07504 876 877.