****** of my money as a client

I bought a DH jacket thats worth R1499 just last month & as I was wearing it somebody notices the stitches was coming out on the side & tearing. How on earth does a jacket of this much only lasts a month, this was a damage that I probably did not even notice when I bought it. Went back to the shop & someone is asking for a receipt, is it normal to keep such even after you have worn the jacket??????? How possible is this?? This is just robbing your customers, I thought this jacket will last me for years as the price & brand would agree with me, BUT yes only lasted for a month. Someone please direct me to the right person as clearly the one I spoke to does not understand consumer rights.

This was Truworth Eastgate & im willing to produce Bank statement as proof of purchase since it was a cash transaction.

If you can fix it I dont have an issue, I bought it because I love it. Provide solutions please rather than asking for receipts, I would expect such from a big company as yours.