Thank you for your support to Tinydeal.
Sorry for the trouble.
The phone works 100% normal with Chinese sim cards before sending out. Can you change a sim card to try?
The phone’s Operating Frequency:GSM 850/900/1800/1900MHZ
Please make sure that the sim card is not 3G.
Please put 1 sim in the phone to try and please change another sim card to try.
And you could adjust your sim as follows : please enter into the "setting",please choose the dual SIM setting .
At last please check whether you have plug the phone in the right way,
please pay attention to the direction when you insert the sim card.
If the problem is still unsolved, please send back for replacing or refunding.
Thank you for your understanding.
Any other questions please feel free to contact us on https://help.tinydeal.com/contact-us. And we would answer you within 24 hours.