iPhone 4 SIM locked

[Fox28]

I have a big problem with my iPhone 4. It keeps displaying "SIM LOCKED "about 2 to 3 times a day! I type my PIN and the SIM unlocks but is not available over network! I have to restart the iPhone to get everything in order. Is anyone there facing this same issue? I called Customer Service and they told me to exchange the micro SIM in the store. So I even changed the SIM but still I am facing the same problem? So what else should I do to solve this issue? Thanks

[Regina]

You can try to unlock your iPhone 4 quite easily without any issues. There are number of ways that you can use to unlock your iPhone. There are many services available for same where you need to only provide your IMEI number to unlock your iPhone 4 completely. You can easily get your IMEI number by typing the *#06# code on your mobile phone or else you can even press the "i" on the LCD to get the same information.

[Simond]

Go to the technician and they will determine if the sim card is faulty, in which case you can try to replace it for free of charge and proceed with activation in a few moments , or if there is a problem with the phone itself. In the latter case, you must then try to quickly contact Apple at 0805 540 003 number within 10 days after the invoice date of your purchase order to exchange your iPhone for free. After the 10 days of purchase it will cost you approx 269$ for repairs in all case.

[Bon-Z]

Incase you are facing issue with the SIM Pin which is also known as the Personal Unlocking Key or PUK then you should try to follow the method given on this link - http://support.apple.com/kb/HT1316. But if you are saying taht you iPhone is locked to the carrier and you would like to use the phone with another carrier then only the carrier to whom the iphone is locked can authorize with the unlocking of the phone. You will have you call your carrier provider for unlocking your device.