Never to shop at city girl in the ridge, shallcross

Hi Guys, just to share a Lil light so that no other person experiences the same thing in the near future. Im currently on crutches due to a post operation on my knee. My son bought me a dress as a gift from CITY GIRL at the Ridge shopping mall in Shallcross. He was given 7 days to exchange if there was any problems. The very nxt day my son left for cape Town for work purposes. I tried on the sleeveless dress a day later nd 1 of the straps on the dress had frayed. I took the dress back today with all the tags nd till slip. As soon the sales lady realised it was a return nd I was not there to purchase from them she had a terrible attitude. She asked y I didn't come in the nxt day, so I said can u see that I needed some1 to bring me here as I'm in crutches, then she asked y I didn't send it with somebody else. So I said I had nobody to send it with. So she went to the owner of the store who accused me of wearing the dress until she compared it to the dresses she had in the shop. I was never so embarrassed and so ****ed off. After a big hassle and arguing she allowed me to exchange the garment. I need to know, what are the consumer rights for returns and exchanges?I will never support this place again. Oh nd the exchange was well within the 7 day period given to us by the store.