i bought a iphone 4 about off a guy the phone was working perfectly as he made a call from it when i was there, i have not used the phone for a while but now when i switched the phone on it says searching then no service.

if i go to carrier and try manual select 3g or 3 network i get a restricted network error.

i have rang up three to check the phone and gave them the imei and they said it was previously a three contract phone and they said the iemi was ok and a pay as you go sim should work ok.

i have not tryed a proper microsim but i have tryed about 4 diffrent new sims which i cut down with a proper tool which i also did on my brothers iphone and it worked perfect so dont think its the sim at fault as itunes tells me the sims mobile number in itunes..

i have tryed airplane mode on off, reset network settings but they did not work.

only thing i have not done is restore firmware.

anyone have any ideas?