Is it a T-Mobile one? Or not? The phone must be a T-Mobile UK one, you must select United Kingdom in their site and voila.
hit THANKS if i helped
Samsung Galaxy S3 Pebble Blue (brand new)
Sotmax v16 ROM, Yank kernel
Old device: SONY XPERIA SOLA BLACK
Unlocked Bootloader, Rooted
Worst phone i have ever had