Cellphone contract- used device delivered

In January a telesales representative called from me from Mobile Tallk on behalf of Telkom they offered me a Hawei P Smart contract of which I accepted and specified the colour I wanted as well a few weeks later the phone was delivered to my workplace and it was a different colour to what i requested and already had images on the phone gallery.We went to a Telkom store in Musgrave centre to verify if the images were starndard images and they said “NO”,I then called Mobile talk informing them of what had transpired and they told me they would deliver a new device and collect the on that they previously delivered which has not happened till this day.In June I called them to inform them that I am canceling my contract as they had not delivered what I had initially requested and I would reverse my debit order since they have not delivered what I had requested.Last month I paid R1000 of bank charges of unpaid debit order fees as they send a weekly instruction to debit my account which is costly to me yesterday they sent another instruction to debit my account, I’ve called them on several occasions and asked their agents to escalate the matter and I’ve had no joy from them.