hi all anyone know where I can get an unlock code for this phone I don't what to spend to much on it as the phone is only worth about £10 second hand its my sons phone we upgraded to Tesco network pay monthly yesterday but unknowing to us we did not know the phone was locked to vodaphone but a asda sim was in it .we don't really want to buy a new phone as he's autistic and loses them and sometimes can't remember where he's put it down all the time anyone help me please I would appreciate it