Sky Devices Platinum 4.5 GSM Unlocked 8 GB Android Smartphone - Dark Gray/Black

I brought this device to take to a friend that lives in another country. The device is unlocked and he is able to use his SIM card, however, the devices locks off (turns off) after just a minute or two on calls, regular calls and internet calls (using apps). I would return it if it was easy enough to have him ship it back but it cost too much and I hand delivered it while I was out of the country. I have purchased this brand before and never had problems like this, which is why i purchased it again, but I am sadly disappointed this time.