5 Panel Aluminum door

I bought a 5-panel aluminum door at the establishment. The delivery guys put the door in my lounge room. When we wanted to install the door, we noticed that there was a crack on the glass. The package is still sealed and not tampered with. I called Takealot and they collected the product. To my surprise this morning I am told that after evaluation my refund has been declined. What I do not get is that the package was sealed. The product was not checked and signed for when it was delivered. This could have been damaged whilst the product was in transit. I really feel this is unacceptable. Why would they send a damaged door back to me if I complained about this. This is day light *******. According to their policy there is a six-month warranty, however all of a sudden there is visible user damage, which I don't know of. Why would I damage something that I really needed. It doesn't make sense, and it is utter nonsense. I am principled and have integrity and cannot lie about such a thing.

I need this to be escalated to management and resolved.