Vodacom 4U Cape Gate - Paying for a product never received

I bought a laptop from Vodacom on the 15th of December last year and never received my Microsoft Key with the computer. When I informed the store they all sorts of excuses - they are still waiting for it etc. I have phoned the store manager at Vodacom 4U Cape Gate numerous times to find out when I will receive it as I can't work on the laptop without it. On Saturday the 30th of January I went to the store to ask for it and they said the IT guy will phone me on Monday the 1st of February to load it on to my laptop. I took of from work so that I will be available but no one has phoned me as yet. This means that I am paying for a laptop that I cant use. I am absolutely disgusted it the service that I have received from this store as they always say they will phone me back and they never do. I will