I have bought a Samsung Galaxy S4 for much lower price. The device model is GT-I9500. Everything works fine, including the WiFi, Bluetooth, camera, display, touch and ever feature works perfectly, expect the SIM functionality.
The handset is SIM-Locked to a carrier (from Saudi Arabia)
I have done factor/data reset on my HTC Desire A8183(Telstra) and now I am not able to connect to the AT&T data. I want the correct working APN settings for this handset. I have followed the below settings: