Disgusting service

We have a Samsung tablet of contract with Vodacom.A good few months ago the tablet started to get extremely hot when charging. This resulted in the screen to crack. The tablet was booked in at the service centre Gateway. After them having it for more than a month they informed us that there is nothing wrong with the tablet and that we dropped it. Always nice to pass the buck back to the customer. They further ignored the fact that of the battery overheating and told us we ha en to pay for the repair of the screen. My mother collected the tablet from the service centre a very uhappy customer, not that it bothered Vodacom at all. The battery problem still continued. You could not touch the tablet while it was charging . This resulted in the screen cracking even more. Again the tablet was booked in at the service centre. This time round they admitted to the battery being faulty and it was replaced. Yet, they still refuse to replace the screen. This could have been prevented if they just did as required from the start! This tablet is still under guarantee. The screen was a result of the battery heating. Is Vodacom once again going to pass the buck yet again ?