Huge damage caused to car due to paint tin not being sealed properly by staff

I bought paint at this store just before Christmas last year. The employee assisting with the paint failed to seal the lid properly and it spilled in my car, causing R12 000 of damages. I went back after the spill and tried to speak to the manager or owner, who had always "just stepped out." Spent a lot of money trying to remove the paint, to no avail. While no one at the store denied liability, could never get hold.of the manager or owner. Finally this year the manager reappeared - he was in fact on 5 weeks leave, yet the staff had me come back again and again saying he if there but just out. The manager promised to sort it out but then stopped responding. I was willing to sort this out amicably but now have no option but to warn other cudtomers and take legal action to recover at the very least the excess on my insurance. Extremely disappointing considering the high standard of other businesses in Midstream.