Alienware M17 R5 recurring issue cannot be repaired

Nearly 3 years ago, I purchased a refurbished Alienware M17 R5 gaming laptop from Dell outlet with 1 year of premium support plus, which I later extended an additional 2 years. Since I have owned this laptop, it has always had an issue that causes the device to shut down for no apparent reason while gaming, which has become more and more frequent over time. I have had it repaired by Dell tech support multiple times with various parts being replaced and I have had to reinstall the operating system several times, but the same issue has always returned. It used to last weeks or months after each repair without shutting down and the problem would occur so sporadically that I could deal with the inconvenience, but it has gotten worse in the last few months, and it seems it cannot be repaired. The last time it was repaired, it lasted 3 days before the problem recurred. The repair before that, it was less than 3 weeks until it began shutting down again. I have reinstalled my display drivers and reduced graphics settings on all the games that I play, but nothing seems to work. At this point, I don't know what to do. I can't keep sending it in for repair only for it to fail again after I get it back. Apart from this one problem,  I have been very satisfied with the laptop's performance, but now I can hardly play games at all, considering how unreliable it has become. I would greatly appreciate any information regarding what it would take to actually diagnose and repair the root cause of this problem, or if that is not possible, what my options would be to have it replaced or traded in. Thank you