phone unlocked but can't use other sim cards
i got approved for unlocking my phone and got an unlock code and did the following step to unlock my phone and was successful. now im overseas to use my unlocked phone but my phone can't read other carriers sim card the signal would show but 4g wouldn't show. tried to call it but says my phone is tunred off. went to see the sim card status it shows the phone number for the new sim card but say no network unknown and says out of service. Also my phone starts to heat up when another sim card inserted. any help? and i need to use my phone quick.