How do I stop my cat ripping the carpet?

My cat Molly does the same thing but she isn't shut in any rooms, she will not use scratching posts she has three of them, but prefers the carpets I have tried using rugs on top of the carpet, at least they can be replaced.

really that's it play with it and keep it happy or it gets bored and does things like that

Does she have things to do when locked in the bedroom? What type of personality does she have, likes to be with people or is she a loaner (sound like she is the latter and wants to be where the action is)?

Hello!

Have you tried buying a scratching post? 

You can also put some repulsive spray on the carpet so she won't approach it.

Hope it helped!