Samsung cell phone: Worst service ever

My Samsung A7's screen suddenly turned GREEN after doing an overnight software upgrade. I googled the matter and it is evident from the amount of information on the web that this is a specific problem with this model of phone. My phone is 6 months old and is housed in a shock/water proof cover. I took the phone to Samsung to be repaired, who in turn sent me to WeFix (who are also beyond useless). I received a quote from WeFix stating that the problem is 'liquid damage' and will cost R3 700 to repair, which is utter nonsense. I have been trying to escalate this problem within Samsung for over a month and am getting absolutely nowhere. They have phoned me at LEAST 10 times to tell me that the phone has liquid damage, which I absolutely refute. The phone was in 100% working order until I installed the Samsung software upgrade. This is a global problem with the Samsung A7 model of phone and they need to take full responsibility for it. Samsung have NO query escalation procedure and NO procedure for customer's to challenge the findings of their outsourced repair partner. I will never buy a Samsung again. You have lost a customer for life. https://www.techradar.com/how-to/samsung-galaxy-s7-problems-how-to-fix-them