Factory fault that leads me to have to pay

I ordered a contract laptop (lenovo ) with telkom, it was then delivered on the 16th of February. Immediately after it was delivered I opened the package because I needed to use it for school purposes. I realised the laptop had faulty of which it was not working properly, since it was Friday I had to wait for Monday for them to open so that I can call them. I then phoned them Monday, told them the laptop is not working properly and I can't continue use it because I have paid for it. They they organised with their warranty company to collect the laptop the same Friday 23rd February. I also told them I do not want a repaired laptop because the reason why I bought I wanted a new laptop not repaired one. Since they took the laptop on 23rd I have not heard from them since. I called them last week wanting to cancel the contract because I needed the laptop then for my studies and was forced to buy another one since I had no choice. But then they telling me I have to pay, for what because it is not my fault. It is their fault that the laptop was not working properly now I have to pay for something that I didn't even used.