I already posted this on the official forum of Sony Mobile, i just didnt know if they will be able to answer so i want to try it here. I bought my phone online on May 2015, Saudi Arabia. For the next 7-8 months it is working, until I experience issue with sim card. It says "No network", even it work perfectly fine in the beginning. Then i started remembering if I drop the phone, because i concluded its a hardware problem. Because once i had the problem, i tried almost everything including master reset to no avail and changing every possible settings on the network. Up until i decided to have it checked to a local technician to which he said either its hardware problem (that he can try to have it phyiscally open to which i decline) or i need to have it sim unlock to which i need pay. By the way there are some official sony stores in my area but my problem is i cant seem to find any enclosed warranty in the box, and i think the receipt i got from the online store might not work. From what i understand about phones being sim locked is that if you bought the phone from a certain network carrier and wants to transfer to another one, not when the phone suddenly got locked even after using it on certain carrier for a couple of months, again thats what i only understand. So here are actually my issues. 1. what is the correct option i need to consider to have my issue fix right away? 2. I dont mind paying an amount to unlock if only its my first time using the phone, so i think its kind of unfair when im already using it. I want to be enlightened on this, like does this normally happen? or was i tricked that i bought a phone that mightve already been used(Im subscribed to a prepaid service, Zain Saudi Arabia) 3. In relation to #2 how to know if where the phone came from, because upon searching unlocking services online, it would require to choose the country and carrier. For z3 compact it would list a certain number of countries in which Saudi Arabia is not included. 4. If i really need to have this unlock, which service online are legit. Because there are a lot online, with varying prices an methods. Plus some website looks shady.