Read the Consumer Rights Act :
https://www.which.co.uk/consumer-rights/regulation/consumer-rights-act-aKJYx8n5KiSl
Your relationship is with the RETAILER (probably Argos, I think). The manufacturers guarantee is in addition to your legal rights.
See also
https://www.homeownershub.com/uk-diy/argos-challenge-xtreme-any-good-122545-.htm#:~:text=Argos%20do%20a%20range%20of,under%20the%20brand%20'Challenge'.&text=is%20meant%20to%20be%20a,%2C%20tougher%20range%20%2D%20Challenge%20Xtreme.
Talk to Argos.
Ghhse
July 2021