Disappointing Service from Samsung Repair

I received a Samsung S8+ as replacement phone from Phonefast in December 2018 and I only started using on the phone Thursday 25 April 2019 and that same day I noticed dead pixels on the top right corner of the screen. I went on Samsung Member and spoke to one of the support agent on the live chat who was very help that told me that my phone has dead pixels and told me to do a soft reset and to update my phone and if that doesn’t fix the problem, I will have to take my phone to a Samsung repair centre. I then contacted Phonefast the very next day as they had supp**** me with the device and which they told me that will send a courier to collect the device and they will be sending it to Samsung for repairs. The device was sent to Samsung Pretoria Repair Centre by Phonefast, which Samsung acknowledge after assessing the device by email that the screen is faulty on Tuesday 7 May 2019, and that they have ordered the replacement screen and ETA on the spares will be Friday 10 May 2019 and a week later after acknowlegding that the screen was faulty they have gone back on their word and calm that the device now has internal damage.

I find this quite strange because the phone practically still new and it has never been dropped. I have done some research online about dead pixels on Samsung phones and this is a common issue that happens to amoled screens all around the world and I know that dead pixels are covered by the 24 month warranty. Now Samsung Pretoria refuses to fix the device even though its still under warranty and wants me to pay for the repair and apparently they say that the device was rejected for a swop out and sent me a quote, which is quite bizarre because now the quote that they sent to Phonefast only states the screen repair and doesn't say anything about the internal damage that they calm the phone has. This really disappointing in how this has been handled and I have never had any problems with Samsung products before.