One of the most terrible service providers if not the worst!!!!

Good day. I took out a contract for a Samsung Galaxy Note 5 with the telkom branch in galleria mall in October 2016. In June of 2017 upon charging my device it refused to charge or switch on. On the 6th of June 2017 the device was handed over to the store as the phone was still under warranty and I expec6ted them to either repair the device or replace it. On the 27th of June 2017 I received a sms from Telkom stating that I have to pay an amount of R7 307,09 in order to repair the device. Considering that the phone was still under warranty and Telkom had confirmed that, I find it ridiculous that I have to falk out an absurd sum of money to repair a phone that was taken on contract and still under warranty. A job card was printed out at the store and it stated that the device was in good condition and no water damage was detected. The attendant at the store confirmed that the device was still under warranty but upon sending the device to be repaired in Pretoria, Telkom had informed me that the motherboard of the device needed replacement and they were not prepared to repair the device. The device has been sent back to the store without being repaired. I am highly disgusted with the service from Telkom as this was a technical issue with the device that they had sold me and I have proof on the job card that states that the device was in perfect condition. Telkom have offered me very poor service and have tried to get themselves out of bearing the costs to repair the device knowing full well that there was a technical problem with the device. I need to be contacted urgently for this situation to be rectified and if it is not I'm definitely going to take this up with consumer complaints.