Nieu May ban chi ho tro nhac chuong nhu the thi khong thay doi duoc dau , con GPRS do may ban la doi dau cuoi nen chua co ho tro cau hinh tu dong . Ban dung nhan tin tong dai qc nua mat tien oan , nieu can them thong tin thi lien he nha cung cap dich vu ban dang su dung .