Vodacom refusing to replace device

I bought a Tablet from Vodacom 4U on the 26 August. However, I found that the device was defective. It had black spots on the screen and rhe keyboard didn't work. I only noticed this on 2 September as I was not using the Tablet because the contract only became active on 1 September. I took the Tablet back to Vodacom to ask for a replacement and the refused saying that the device was out of box for more than 7 days and insisted I send the item for repairs. I sent the item for repairs and received it back and it still had the same problems. I then asked for a replacement which they refused saying I need to send it back in for repairs.

Vodacom is useless. They have terrible customer service.