Disgusted and disappointed at the service and product

I purchased a Hisense 49" TV unit in 2017 and this year the color started fading, the unit has a 4 year warranty and I contacted them and they sent a technician to collect and repair the unit. 3 months later the TV is black with no color only sound and without even checking it they tell me it can't be repaired I must contact the store where I purchased it for a credit. My account is closed at Home Choice and they are not assisting me. All I want is my TV to be fixed, what is the warranty for if they can't fix it. My warranty is with Hisense not Home Choice. I WANT MY TV COLLECTED AND FIXED. Warranty is to repair damaged goods and I have nothing to do with the color fading on their TV. Also none of the AGENTS Nomsa and Sibusiso working on the complaint have bothered to call or apologize they just tell me to get a credit. BULL**** SERVICE