Software update

I had the iPhone 6s had as in I did a software update on my phone on Thursday the 18 January 2018 woke up on Friday and my phone is stuck in a reboot mode switching on and off the hole time . so I phoned apple on Friday explained the hole story to her said that I should take my phone to my serves provider who is Vodacom ...so I take phone there and they tell me after a year my warranty expires on a TWO year contract that I pay R1300 every month ,I said ill pay for the software update just fix the pone told me the phone does not want to update take it to apple ....get in my car drive to the glen apple store explain myself again he takes the phone and 20 min later tells me the phone cant update I need to pay R5000.00 to fix it I already paid R 15000.00 for the phone I will not pay my Vodacom account for not having a phone and no 2 year warranty and I will note take an apple device ever again