A.Saleem,
Don't buy that crap!!! I got my IPhone S4 in Kuwait and I was having the same problem!
Try backing up the phone to your computer, then erase everything all setting, data, everything like if you were to try and sell the phone. Then turn the phone off leave it off for a couple of hours. Then take the SIM card out and turn it on. On the welcome screens set it in english and put for location US. You won't be able to activate the phone then plug it on your computer and it will tell you; you need to insert the SIM card. Put the SIM card in and restore your Backup.
This is how I solved my problem, and now my facetime and Imessage work just fine.
Let me know if this helps. I lost facetime in October last year while I was in Kuwait and I just did everything I told you yesterday still in Kuwait and it worked.
Good Luck!