phone keep on over heating

I have a Samsung S4 Mini I took it twice now because its faulty i have this phone now for 1 year and 5 months. it overheats freeze and the battery is draining very quick. <br> <br> It was in for repairs but the say there is nothing wrong with the phone they only did a software update. this does not make any sense at all. I got it back and when I started installing the apps that I use it stated doing the same thing freezing and the phone feels like its going to explode in my hand and even if I dond hold it in my hand its overheats this is not normal I need to put it in the fridge to cool it down because im scared that it will explode. I cant keep on sending this phone in for repairs and then only to find that they say there is nothing wrong, i know its not normal for a phone to overheat like this. and freeze like it going out of fashion. <br> <br> I would like to get a response, form Samsung and Vodacom because my contract is with vodacom im currently paying a contract which include a celphone but i can not use my phone.