********* and breach of contract

Sold our Mercedes A 180 Cdi to this dealership the car was inspected by Stelios and he agreed to buy it we both signed the the purchase of the car . We left the car and we would await to get paid. The next day he phoned us to say that there was paintjobs done on the car and it was very bad quality and poor workmanship.The next day we went to the dealership and a Panagiotis told us that because of the paint jobs he would now discount the original selling price and he demanded to reduce the original selling price by R50 000 he started to find lots of faults and he was full of excuses. We however refused and took our car back. This is not ethical and its disgusting business ethics once you have closed a deal there is no backtracking they had sufficient time to inspect the car the day we took it there . Bad business dealings. We felt ********** and time was wasted .