Damaged phone

I am very disgusted in the service i received from the westgate johanesburg branch. I recently sent my phone in for repairs and after the phone came back from repairing thr charging pin it was just glued together. I didnt see this and the phone was always water proof as it is a aqua m2. After swimming and taking under water pics the back part of the phone bent open and got water damaged. I sent the phone back to the store and booked it back in. I was informed that they could fix the handset and also wouldnt replace it as it was water damaged! Ofcourse it was due to the repair not done properly!! Then the consultant at the store based cell c service on \this is South Africa ma'am\". And now im still liable for the repair charges?? I dont think this is very fair. I would like this to be sorted out please. "