Refused to exchange

I bought a golf t/ shirt at Total sports in Durban west Street on the 8 of December 2017. my son wore the t/ shirt once and when I washed it, it just tore a little bit right at the bottom of the buttons. so when I brought it back for exchange the manager refused said it was not a manufacturer's faulty and these golf were sold out and non of the customers came to complain I'm the only one and she said it shows that something poke a T/ shirt. Which is not true and I still believe that it manufacturer's faulty then I asked her boss's contact details I called him then he said I must take a picture and send to him I did that he called me back and said they can not exchange it because it not their manufacturers faulty bla...bla... support his manager and that was it. I'm so disappointed coz I thought I was buying a quality for R379 this was not the kind of service I was expecting from Total sports they don't care about their customers and there is no such thing as? manufacturers PLEASE HELP I still believe I was treated unfairly and something needs to be done.