Broken Shoes after 2 months

I bought a size 5 pair of Toughees from Edgar’s for R279 in the 3rd week of January now 2 months later the 1 show is broken at the heel. I have never had a problem before my daughters previous pair lasted a year as she is not hard in shoes. I find it completely unacceptable that I now have to replace them again. This was bought cash and not on an account so besides my bank statement I don’t have any slips for this purchase.