Unlocking iphone 5s
Hello,
Recently I tried to unlock my iphone from EE uk carrier. Today I got message that unlocking is completed. However, I still cant use my iphone with other sim card. I followed all the instructions to complete unlock in few ways and many times and still nothing works. So, I called costumer services, they check my account, told me to do everything again and etc., I told them that I completed every step in instructions and nothing happened. Then they said to me that sometimes its impposible to unlock iphones, how it could be, apple can lock phones but can't unlock ?????
iOS 8.3