Invalid Sim (Sim is from carrier that not supported)

Hi everyone,

I just bought a second hand iphone 4. The previous ownner informed me that he had bought the iphone from an Apple store from UK and for two years he used it in Cyprus with a local network carrier (he told me the iphone isn't locked). After he bought a new phone he shut down the iphone for one and a half year since today that i bought it.

After inserting my sim card I get a message saying " The SIM card is from a carrier that is not supported under the activation policy that is currently assigned by the activation server" and therfore I cannot activate the phone. The crazy is that I am using the same carrier as the last owner...

Any advise?

I have also try to activate it through itunes (I am getting the same message), I did also a hard reset but nothing.