Apple products unreliable

I received a replacement Apple watch in February. Four months later the watch stopped working, doesn't even switch on. I have sent it in for repairs and the problem couldn't be identified and I was told that I need to replace it with a new watch. I find it difficult to believe that a watch of the Apple calibre can merely stop working after 4 months. Unless I was given a faulty watch as a replacement unit. This is not the quality of the service one expects from a multinational technology company.