Why can't my phone detect my SIM card?

The device might be set to Airplane mode or there is poor contact between the SIM card and phone, please turn off Airplane mode and re-insert the SIM card

and try again. Your SIM card may be faulty, please request a replacement from your service provider. The SIM card deck may be damaged due to bad handling, 

please bring the phone to our service centre. Your SIM's frequency band may not adapt your phone, please double check your telecom carrier.