Damaged baggage

I was on Mango Airline Flight JE 139 yesterday 19 September 2019 from OR Tambo to Cape Town. Upon arriving in Saldanha Bay for business I realised that I could not open my suitcase. The lock and zipper meganism was removed through tearing the material at the end of the zip. Obviously they realized that if they then open the suitcase as I had to do you cannot close the suitcase again. So the suitcase is now rendered totally useless. Tried to phone Mango but NO ANSWER!!!