Tablet still not fixed after 5 months.

We have an contract with Telkom. We had this problem from the start where the tablet will suddenly go blank and and to be recharged, we would fully charged it and then after an half hour the same will happen. we will work on the tablet and it will go blank. We had trouble switching it on and we mentioned all of this when we FIRST handed it in. But the matter of the fact is, what ever you use the tablet for, games, emails, what ever, the tablet and the battery was still under warranty when we handed it in. This was still under warranty, but NOTHING was done by Samsung or Telkom. There was no letter or indication what was wrong. weeks later she received the tablet and asked what was wrong but there was no letter to indicate. she took it home and it did exactly the same thing, the next day she took it back and handed it back in. Now waiting for 3 weeks is not our fault and then handing it in so many months is not our fault the warranty then expired. all of a sudden it was the battery. the battery was still under warranty why did Samsung not replaced it then. We waited 5 months for our tablet and still waiting.