I opened an account with Lewis furniture store Margate and they did not deliver the wardrobe I bought from them and of which I'm still paying for it

I opened an account with Lewis furniture store Margate and they did not deliver the wardrobe I bought from them and of which I'm still paying for it. Instead they delivered another wardrobe which is smaller then the one I ordered, this has been six months now, and I'm still waiting for it. I'm very disappointed in them.