Poor service at vodacom at a store

I am utterly disappointed in the service that has been provided to me by the consultants based at the Vodacom cellular outlet at Forest hill mall. I am due for an upgrade. I had requested the upgrade for a Tablet that they did not have in store. I was promised that i would be contacted as they will order it. Two weeks later i called the store, a gentleman informed me to come through and that they had two of the gadgets in store. When i got there I was told that there is nothing. I have been going to the store to check if they had received 'ordered' tablet to no avail. This has been going on for almost two months now. These people have never fulfilled their promises of calling me. I refuse to be associated with Vodacom. I am going to cancel my contracts.