SmartPhone Network Denied

[Guest khattkoo]

I am currently using T-Mobile in the US so i got my Smt5600 remote unlocked. It was working great over there, I came home for VAcations to Dubai and Pakistan. And my phone refuses to pick up any network coverage. I tried 5 different Cellular services and in Pakistan and i get access denied. MY T-mobile has roaming contracts with two of Pakistans service and even that doesnt pick up anything. when i tell it to search for networks it says Unable to save settings verify that you have coverage and that the setting is supported. I have no idea whats going on. Please Help