Is Appple or Service Proivder, who is fraud?

Is Appple or Service Proivder, who is fraud? Bought iPhone 5S for my wife from Boost Mobile, after six months of use, due to our move we have to change service provider as we don't get boost signal any more. Paid full price for the phone. Boost mobile is saying phone is not been locked by them. Tried another compatible service provider and found out phone is locked. Called Boost and they say phone is not been locked by them and Apple can help to unlock. They don't have any procedure to unlock it. Called Apple and it says, only boost can make request to unlock the phone, you tell boost to send request. Boost says they don't have procedure and phone is unlocked, call Apple to help you.

Thus I am just going in circles. Both companies say go to each other and no one wants to help. Who is Fraud, whom to trust?

Sorry I have not expected this type of treatment from Apple. No Support at all. That was our first Apple purchase and lack of support is dissapointed. I had high regards for apple and now not any more after this experience.

I only want to know, can I use phone with Tmobile. what do I need to do? How process works and Who is right, apple or Boost, whom to trust?