Poor Quality Defy Kettles

Bought a Defy Stainless steel kettle from Pick n Pay Hypermarket on 22 March 2024. Had to return it a few days later as it refused to switch off. Went back to Pick n Pay on 29 March and returned it for another one. The next day it did exactly the same and refuses to switch off. This is also dangerous for overheating and possible explosion. Model Number WK728X. I am 79 years old and live far to keep going and returning it. I have already made 4 trips to the store to try and resolve this. The cost of petrol has already exceeded the cost of the appliance. I am really disappointment with the quality from Defy and I need to someone to come and pick this kettle up and resolve this issue as I live very far from the retail store where the kettle was purchased.