Why state that they have 6 month warranty while they don't?

In November 2023 I bought Premio x3 Bluetooth headphones with the case for R300. In February 2024 they stopped working on the left side when I tried to return them since the slip shows that they were under warranty for 6 months the shop declined them and told me about 7 days. Why should they state that they offer a 6-month warranty if they don't take them? why should they lie?