I need to unlock my china mobile A8000

Hello,
Hi I bought a china mobile model is a8000 but the problem is when I put any its not working can you pls tell me how do I unlock my cell phone this since I bouhgt a year any half I've never use it idont know who I'm I gonna call I keep trying to pigure it out and keep asking to people to how to unlock my phone they this is suppose to be unlock but I told them its not a unlock since I bought this phone can you pls help me if you don't mind I appreciate that thank you