Platinum Warranty and Mecer Guru pro

I took out a contract on a Mecer laptop with Vodacom over the phone. Platinum Warranty is the people that you must contact if you have a problem and they also do the repairs on the laptop. We received the laptop just before lockdown level 5 in March of 2020. Since 15 October 2020 we have send this laptop and received a new laptop to Platinum Warranty so many time I stop counting . Every time they can not find the fault. My daughter use it for university, with the classes being online this laptop will in a middle of a class shutdown or freeze. Nobody is willing to take time a look for the problem. This is being going on for a year Is there anybody that can help me solve this problem.