The Gabb thing is the fault of the parent.

By buying a child a locked down device - a hostile device that few would have accepted for themselves as a child - they marked them as 'being a child' rather than blending in with the rest of the people on the Internet.

By marking them this way, they advertise the child to the predators of the world.

This is someone who is twelve. They aren't six. Life involves risk. Stop playing with account controls and let the person play Minecraft. This really isn't that hard.

Having thoughts about physically breaking a child's holiday gifts - of doing that in front of them - is suggestive of being a pretty awful person. You can't figure out something that the child does not want, so you want to break their stuff?

How much longer do you intend to keep this routine up? Is your objective for them to go no contact? What are you seeking here?