Kitten Problems, Please Help!?

My 23 week old kitten is being a pain, she keeps climbing up the Christmas tree, chewing through wires, pushing ornaments off surfaces and just generally causing havoc around our house. We shout at her and put her in the kitchen and leave her there for a while, let her back in but this doesn't work. She still behaves like before. She is on the verge of being handed back to where we got her from. Anything I can do to make get behave, new techniques?