Very poor quality goods and rude staff

My mom bought a gas heater Cash in June 2024. In September the heater was not working anymore. She went back to the store and reported this. They asked her if she still had the slip she said no she didn't think she will need it because she trusted the brand and also the shop, she was advised to bring back the heater of which she did.

In October she went back to get feedback regarding the matter, a very rude lady shouted from her desk asking where's your slip and harsh words were exchanged between them and she left without being assisted.

She went back again in November and was told that the supplier does not have stock. It's now 4 months later she has not gotten feedback.