Tired of bad service

Vodacom offered me a data contract with a tablet. I took the offer and they said that they will deliver the tablet to me at work. Instead they delivered a ****le. I was very upset and told them they should cancel the contract and pick up the the ****le. They picked up the ****le and never canceled the contract. After numerous phone calls and even going in store (as they told me I should) nothing came from it. Ever since I have been paying for something I do not have or do not use. It's ridiculous.