Want to return furniture as material used was not agreed upon

I have purchased furniture from a shop in Dhanori. The material agreed upon was plywood, and the delivered material is Particle board, also the items are undersized. Earlier shopkeeper once visited after repeated complaints and agreed to take the material back and return the money. But when I visited him after he refused to agree and threatened me. Also said do whatever you can do. He also refused to give me bill earlier, and said he does not provide the bill. I have the audio recordings of these talks available with me. Please suggest how do I get my money back and the items returned.