BAD REPAIRS - AGAIN. For the 4th or is it 5th time

Now I am getting really mad! I think I must take this case further and go and see a lawyer. We are struggling with my son's Sony Xperia Z3 from October 2015. I slipped and fell from 12 stairs with his phone in my hand. Only the frame was bent. I took it in at the Ceres branch and they send it to Vodashop Tygervalley for repairs - they quoted R2800.When we received it back, something was loose inside, they sent it back again. The second time it wasn't waterproof anymore, so I sent it back. They quoted another R900 but I put my case on Hellopeter and they \tried"to fix it. The 3rd time the overheated and there was water in the camera. They told me it had 95% viruses on the phone. I received it back last week. The back of phone was little bent"