REPAIR MY PHONE

My cell phone was in my top pocket, and when i tried to take my phone out, it was so hot that it fell out of my hand. The phone overheated which hasnt happened before. i took the phone into woodmead repair centre. The agent that took the phone in, basically wrote hes own report on what the issue was on the phone. he did not take down the problem that i came in with, he made up hes own mind on what happened. I than received a quote via sms to the value of R1700 but my phone is under warrenty so there is no way that i will pay for this repair. The overheating caused the damage so i refuse to pay the amount. I need assistance as soon as possible as i feel very used. I need my phone repaired because of the consequential damaged caused.