I never had a bad service before this is too much

I bought a tv stand since 15 october 2014, and they told me there was no stock they will be a stock in december I agreedn so since december I waited for delivery until now, when I go them they said they don't see the invoice so they can't be able to give me tv stand, is this my problem? I asked they said no they will deal with the matter even now I'm still waiting, I'm so fed up