No "GSM/UMTS" for International use on my L720. please help

I bought S4 mini (L720) from ebay, i can admit i never read the descriptions very well. i have already unlocked the phone and noticed it doesn't come with "GSM/UMTS" . please is there any code or app that can enable me to use use in my country. it's pain i cannot browse with my much await android phone. please suggest a way to solve the problem.


thanks