Mac mini extremely slow getting a refund

I bought a Mac Mini yesterday late 2014 model. I spent two full days and over 10 phone calls and chats to Apple Support to try to fix it from being EXTREMELY SLOW. I Started with a PRM re-boot, then an OSX re-install that took several hours. It got better but the Mac Mini is still too slow to be workable. It takes from 80 seconds to load Apple apps to over 3 minutes for Word for Mac 2016 to load up. The last call with Apple support was the last. I'm taking the Mac Mini back to the store and getting a full refund unless anyone here has any suggestions? There are many un-answered comments about the Mac Mini being extremely slow. The Mac Mini is a DOG. Do not waste your time if any slowness is experienced! Horrible product experience. Plus, over two days to get a Genius Bar appointment - not good. A very Bad Apple.