Hello Guys, I will like to get some urgent information , I brought a Sony used phone 3 weeks ago , All my apps are working perfectly, I cal use my Whatsapp , download music and film with my cellular network but my problem is , I cant make and receive calls or even send and receive text message .When i attempt to carry our this function , the notification i get it "mobile network not available " but signal strength is full and while this error message show, i can still browse with my cellular network at full speed.... I need help please
