Q: Sim not valid - Still receives calls - iPhone 5

Hey everyone. I'm having the exact same issue as alot of people ive being reading on this forum. The only difference that i have can still receive calls, at least ive not seen anyone yet with the same exact case. My signals dots are full, carrier name is displayed and i have 3g when not connected to wifi. How is that possible if my sim is not valid???

Yes it is carrier locked, but is the same as my sim.

Please help. I need my phone back.