Tablet went in twice for repairs but was never rep

I purchased a Samsung tablet in November 2014 for Cellular city. I sent the tablet for repairs in December because it was not charging and heating up. When sent to Vodacom Gateway, the tablet was formatted and all my downloads were removed. The was no difference in the tablet. I sent the tablet again in January and again all my downloads were removed because of formatting. My tablet is still the same, not charging and heating up all the time. I am sick of the technicians only formatting the device and not solving the real problem. My device is getting worse and the technicians do not know what they are doing.