HTC SENSATION (think its been blocked) +

I bought this HTC SENSATION around 8 months ago! had no issue great phone. But over the weekend stopped calling out??? still shows network coverage and can use the internet via 3g and wifi. so guess the person i bought it from waited a while and done a dodgy (w****ker) Anyway no use to me but might be good for abroad and would like to get a little money back! comes with everything BOX CHARGER USB HEADPHONES (never used) MANUALS this is not stolen otherwise i wouldnt have all the accessories. Cash on collection only North or Central London