Unsuccessful in making out going calls

Hai every one,, My name is ranjith and i own a iphone 3gs 32 gb china phone . Ihave not been able to make out going calls from my mobile since i bought the phone . the message displayed is not allowed to call when i try to make a call ..please suggest me one this . i dont know about any registration has to be done before making calls ..

and another thing is that the memory .. there is only 1gb memory in my phone instead of 32 gb .. ..Also give me advice on this ...