Contract phone warranty

I bought an iPhone contract phone at Vodacom shop Brooklyn mall Pretoria next to mugg and bean on the 13 April 2017. It was starting to give me problems like restarting, then I went to Brooklyn Pretoria Vodacom shop next to mugg and bean on the 26th September 2017 for them to fix it for me since It's 6 months old and still under warranty.

I then received a message from them on 12 October 2017 that I need to pay R5812.86 for them to fix the phone. I declined the R5812.86 quote from Vodacom repairs shop at Potchefstroom and went back to Brooklyn Pretoria Vodacom shop, then consultant told me that they will give me my phone un-repaired and I will have to continue paying for that phone every month until my contract ends. I asked him how do I pay for the phone that is not working for 1 year and 6 months. I called Vodacom call centre to cancel my contract so they want me to pay R6000.00 which I don't have.

So I am requesting my phone back in a good condition since it is still under warranty please!! Job No: ********** 7