Shoprite refusal to replace pensioners kettle before 1yr warranty expires

My mother a pensioner bought Ottimo cordless kettle from shoprite Maitland on 10/08/2019, the kettle then started giving problems by not switching on, she took kettle back to shoprite Maitland because it's still under the 1yr warranty/guarantee. The staff member at shoprite refused to replace it because according to her the kettles element had broken/damaged. According to the warranty on manual if the product is defective or not in working order due to ordinary wear and tear. What is the point of having a 1yr warranty/guarantee on the product if it is not replaceable of something goes wrong with the product with in 1yr. It can be costly for a pensioner to replace these kettles every couple of months due to defect parts that's not covered by their warranty/guarantee as stipulated on the items boxes