Being billed for a device I never received

<p>I took out the new samsung galaxy S8+ when it was released. Received the phone but I did not receive the promotional accessories with my delivery. I had to return the phone and when it was returned I asked them to cancel the contract because I was not satisfied. I was told I am able to do so and the contract was cancelled. </p> <p>I was then debited twice since I cancelled and no one from can assist from Vodacom. They're saying it's ***** but I told them I cancelled the contract before receiving the phone. I have since taken out a separate contract and now I'm being billed twice.</p> <p> </p> <p>Please assist </p>