They won't fix my under warrantee phone

December 27th 2014 I opened a contract with telkom. November 2015 I realized the screen started to malfunction cause it refused to touch and would go blank ( iPhone 5s). We then took it to telkom mobile in Irene(where the contract was initiated) on the 2nd of December and handed it in. On 7th Dec 2015 I get a message that it has been booked in [Dear BOITUMELO, your phone has been booked with ***] .This information was immediately given to Telkom mobile such that they subsequently sent the message below on the 19th- Dear BOITUMELO MASITISHO, your iPhone 5s Apple has been allocated to a Repair centre for repairs - ***. then I get a message and the following day a call from Jessica regarding a quote of R5419.71 to replace the phone because it was out of warranty. ***. On further questioning I was told it has dents.She agreed to send me pictures of the dents she was talking about but never did till today. I haven't had a phone for months,while telkom continues to receive monthly payments for the phone and airtime.Now they tell me to pay to get it replaced because it's out of warranty yet they received the phone while still under warranty.