Refuse payback after incorrect service

Louws cut two sets of keys for a holiday flat on the West Coast which were rented out to two different families. When the first renters arrived at the holiday flat they discover that the keys do not work. I was very embarrassed and had to make emergency plans to get a new set of keys cut from spare keys which I had to send to the holiday resort as an emergency. The keys of the second group also did not work. When the faulty keys were given back to me in Bloemfontein after the holidays I took it to Louws Keys and ask to be paid back the cost of the two sets of keys. They offered to alter it so that it will work, but I have no use for it anymore since I had the original set as well as he set cut at the West Coast as an emergency. They manager called the owner but he refused to give back my money and only want to alter the keys. There are many other cases where keys cut at Louws keys did not work.