refusal to accept damaged goods

Bought an item from MRP midrand,got home-the tip was broken.I wanted2 exchange it&happened to go2 the rosebank branch on Saturday,asked the lady2 EXCHANGE it4 other items I was buying (R300 worth).MAUREEN implicitly said no.I explained that I'm exchanging because it was bought damaged&that I didn't break it,but she continued2 raise her voice,shake her head&look away from me saying NO NO WE CANT ITS BROKEN.There were people around me&my boyfriend came over2ask her but she was not listening2our explanation.Is it policy2sell damaged goods then refuse2exchange them??Or2 refuse2 exchange at another store?Is that not why numerous branches exist,4 customers convenience?y am I being treated like an undesirable??I am disgusted with the pathetic attitude&bad process knowledge of your staff.I even told her2 call Midrand&check if I can't return it here,she SAID \Whats the point of calling Midrand