Bad quality of phone S7

Firstly my wife purchased a S7 a year ago.the phone fell and the screen got cracked went to the Samsung store and I was told that the screen won't be covered due to it being two months out of the warranty period.i left it then since then the phone started getting hotter and hotter I ask for advise at the store and it was told that it gets hot with a lot of usage especially during charging.now the phone doesn't hold charge for long and the cover is coming apart due to the swelling of the battery and I have to expect that a phone that isn't even A year and a half old gives so much problems. I really thought that Samsung would bring a out a hassle free product.Rather leave the brand and go to another brand like I phone or Nokia.the phone is going to explode.