Hi All, My father has Samsung Guru 200 mobile (SGH-B200), with Airtel Sim. Saturday he had been to Hyderabad to leave my brother for his work place, From Sunday onwards his mobile is been blocked for outgoing calls, he came back to Bangalore today. The problem is when i put my Spice sim from my N73ME to that mobile and outgoing is working fine, the Airtel is also working fine (outgoing calls) in my N73ME, but again when i put back the Airtel sim to B200 mobile, outgoing calls is not supported, it says "Service Not Available". I contacted the Airtel customer care, they gave to type in this code *#333*0000# and call, when doing this it says "System Busy!! Please Try after Sometime" Guys please do help me, what may be the problem. Only Airtel Sim is not working in the Samsung Mobile.