No return on bad quality product

I bought a bike in January 2015.Since then the bike is more off the road than on. Everytime I want drive the bike it get a puncture. The rim is cutting the tube. The paddles is unstable and causes me to fall.I tried speaking to the manager and he said that I cant return the bike but he said that the sales assistant ddnt inform me about the products return policy.They just wanted to make a sale. I don't want the bike and want to exchange it for something else. Or my money back