Disappointed and unhappy customer

I received bad customer service from Pack n pay clothing mams mall, last month I bought 2 pairs of school shoes which I lost the receipt and now the onther pair it torn and when I told my child to take them to the store for exchange as the promised 6 months warranty, the manager refused as the shoes are torn and they said they only exchange something that they will be able to resell. So I went to the store thinking the manger will come and explain to me as she was rude to my kids, she didn't bother her self as she left the cashier to answer my question. Now I bought my child new shoes but the service I received there it was soo poor and I am not going back to that store again as they refuse to take Thier damaged shoes and give me new shoes.next time the manager in charge should talk to the customer see ways that she can help the customer who lost her slip, at my work place if customer lost her slip they are many ways we try to retrieve the proof of purchase, 1. We ask how they customer paid for the unit ,if by card we ask for bank statements so we can see the date of purchase or we search the customer on they sestem by her details. It's sad because pick n pay have this own lebel but still no help.