Nothing cute about these pink gumboots sold in a workwear store

i bought furlined all terrain gumboots in july 2020 and where the boot has a pink detail on the heel that is welded in the grey to look cute and has split open...i wear the boot on my smallholding which is like anyones back garden and i visit my stables...2hrs in morning and 2hrs in the evening they refuse to believe that the split is bad manufacture they want to replace a R600 with a R85 pair i have asked for them to repair and they refuse