Samsung S8 screen replacement - Product/Benefits not sold correctly

I send MTN an email of my utter disappointment with regards to my NEW Samsung S8 cracked screen on the 22nd of March. A Week later I completed a query form via the MTN website. Till today I have not received any feedback or contact, only an automated email respond with query number ********** 3. When trying to contact the call center, you have to hold the line for ages. I need assistance! My complaint was to both MTN and Samsung SA. I've received contact from Samsung SA that informed me that they can not take responsibility for the cracked screen to be replaced for free as the phone is 3 months old and that MTN needs to take responsibility for the replacement as the sales team did NOT provide me with all the necessary information and cover relating the the Samsung S8. This training and information is provided to all service providers to ensure that they sell the product correctly. I was NEVER told that you do no longer qualify for the free screen replacement unless you sigh up for the cover for something like R62 per month. If I was told this, I would have taken this cover seeing that this is a general problem with the S8 and that it is so expensive. I'm on contract with MTN and is still paying off for a product that was barely 3 months old and no longer working as it's suppose to. Where is the fairness in this, how does one call this good business practices. I've been with MTN for years now and have never been this disappointed. I don't feel that I'm being treated fairly.