Telkom billed for a Phone that is in thier Store.

I went to Telkom Sandon on 26 April 2018 to open a contract, a gentleman by the name of Richard Lephoto assisted me he me told that they only have the phone in black, I said no I don't like the colour lets cancel the contract. He said the cancellation will take 7 working day, on the 11 of May 2018 I called to check if they have cancelled the contract they told me it was still in progress. To my surprise Telkom has billed me for a phone that I don't even have and they can assist me a debit order will take place as scheduled. How can they bill me for a phone that is in their store? can someone assist me. I am really disappointed in Telkom. :(