Poor service from Samsung

Good day, today I want to complain on the bad service I got from Samsung, December 2013, I bought a Samsung Galaxy Tab 3, on contract with Vodacom, Oct 2014 I think was the first time I took it to Samsung Constantia complaining of the tab loosing power and not charging properly, I then spoke to one of the managers then (Dwayne) and also asked them to please test the battery because it looses power quickly, then I took it back to them again in Nov 2014 speaking and complaining to Dwayne about the same thing, they replaced the pcb of the tab saying that was the problem, but did not check the battery as I asked, when I got it back then Dwayne still told me he would phone to find out if al is ok but he did not, now I took it back again Feb 2015 still complaining about the same thing now eventually they tell me its the battery and I should pay R855 for a new battery, I was so upset I mean the phone is on contract but the warrantee on the battery is apparently only 6 month no one told me that now they try to make it sound as if its my own fault for waiting from Nov 2014 till now Feb 2015 respond again. I waited for a week and phoned then they haven't even looked at my tab yet.