Im using dtek 50 bought from amazon. I think my phone is refurbished or repacked. I have checked that no screengruard with blackberry sheild logo was there when I unboxed it. Also the pin used to open sim tray was not placed where it should be. Can you please tell me how can I check that. I tried *#786#* and *#*#786#*#* to open RTN but didn't work, it goes blank when I dial. Any suggestions champs.