What do I do if the sim doesn’t work in my phone?
If your Sim card is not working in your phone means it is understood that it is locked to some network.So to use it in all networks you need to unlock it.
I have experience in unlocking my phone with the help of Unlock-Zone.com where you need to mention your phone model,network and country your phone is locked to.They provide you with unlock code and free unlocking instructions.After unlocking your phone you can use it with any sim card you decide.