Appalling customer service

I went to Mica in Lenasia (Signet Terrace) today, as I needed to buy a few things, especially paint. After purchasing the paint it was loaded onto the trolley with a couple of other items. As I left the store I noted that Mica employees were busy with some sort of spray paint that connected to some cable. The trolley went over the cable and one of the paints fell out of the trolley upside down. I immediately went back into the store and asked the manager to exchange the paints no he refused. He spoke to me rudely and told me that once I was out of the shop it's none of his business and he can't exchange or refund me.

I have several problems with the incident: 1. There was no indication that there was any construction happening, no signs of caution, nothing. 2. Upon speaking to the manager he spoke to me rudely and refused to give me his name. 3. I called the head office, spoke to a lady named Joe she too refused to help me and told me that she can't do anything if the manager refused. 4. I did not want a refund, I simply wanted him to exchange the paint, since the construction happening at HIS store, caused the paint to fall.