My Sony Experia Etra mobile phone could not switch on after i bought with contract from MTN within 14 days

Hello Peter please assist My Sony Experia Etra mobile phone could not switch on after i bought with contract from MTN within 14 days.

I Webster Sihlangu recently purchased a Sony mobile with contract from MTN on 16 December 2017. The phone eventually couldn't switch on on the 28 December 2017 which i took it likely thinking MTN will resolve the incident since i just bought it and it has a one year warranty. I took the phone back on the 06 January 2018 to MTN store where i bought it (Boulders Mall) where they referred me to their repair store. I took the phone to MTN repair store but they didn't administer my phone, someone just had a look on it and declared the problem has to be sorted out with Sony repair couriers whereby they immediately gave me the courier' s details to contact them fo further assistance. I was told i will not pay any charges since the phone it is still under warranty but now after the Sony repair courier received my phone they then sent me a quotation stating i should pay R3800 for the phone to be fixed. In the event the Courier fee of R500.00 and Quote Rejection fee of R171.00 is payable. The quote rejection fee is purely to compensate the technician for the time taken for the assessment and attempted repair. This is totally ridiculous and frustrating me since the MTN did not want to handle this problem rather sent the customer to resolve the matter with the third party service provider (Sony). I still have to pay and complete the contract for the next 24 months for the faulty device that has been given to me. This is poor service i ever had in my life.