Incredibly rude manager using foul language to customer

My husband visited Dulux Parktown North today (27 August 2022). He asked for a water based non drip black enamel. The young assistant found him a product and he paid for it and took it home. When he opened the tin he found it was neither non drip nor pure black, . The only criteria match was water-based. Since he specifically wanted a black to match existing paint, and a non-drip he returned to the shop an hour later. The manager said that they did not have a non drip black in stock and refused to give a refund for the wrong supply. He then called my husband a F**ing stupid old man and other foul language. He left the product with the manager and accepted that he was not going to reimburse him or offer a credit. He advised the manager that he would be writing to Dulux to complain about his unacceptable behaviour, and that he would not be purchasing Dulux products in the future.