Bad customer service from staff to manager. Being treated like a child and talked back to with attitude

I went last week to purchase a baòg from the foshini store in mall of africa. Only to found out that they have put damaged stock on the sales floor. I then went back yesterday to return the bag and asked then to check which store has it so that they can send it to them of which it will be easy for me to collect. I'm then told that I must pay a fee of R75 for the bag to be delivered to them. I then ask to speak to the manager because I feel that the damage was not my fault. I have never experienced such bad service coming from a managers level the lady was shouting at me like I am a little child and telling me that I should of checked the bag before buying it and so on. I'm not happy with all with the service and treatment that I got from that store!!