Damaged luggage bag

On Saturday morning, I was travelling from Cape Town to Durban however my luggage was left in Cape Town. It was then sent to later then from Durban to JHB and JHB to Margate since I stay in Margate. I have since received it however it has a very visible crack. On check in the luggage was in good shape with no crack. This is the second time wherein I have a problem with a luggage with your airline. The lady who assisted in Margate to a picture of the crack. This is a hard case that cannot be repaired therefore I am requesting the replacement as this is your fault. It was an inconvenience to go home without my luggage, I felt so naked without my clothes but to have my suitcase damaged with a big crack is just not acceptable. I picked up my laptop on Monday and the lady at the airport took a photo of the crack, she told me that they will not replace or repair my luggage, How so when I left left it unbroken. No one has contacted me that is how bad their customer service is.