Rude Staff at PnP Northgate

I was at PnP Northgate (Food) hoping to exchange an item of clothing that I bought at another PnP in the same mall yesterday.As I was told by the lady in the kids clothing department that I'm able to exchange as long as the tags and everything seem fine on the item, and it was so but when I got to the Returns tills I was met by 2 ladies who were so rude to me and I still do not understand why. The 1st lady was shouting at me that telling me that she is a supervisor and my goods will not be exchanged and the other 1 was telling me that I should go to the PnP where I bought the item because that other PnP has issues when they have to exchange goods from them. 1st of all I do not understand where I get in there because whatever issues both stores have amongst each other is non of my business. The attitude and rude way they both spoke to me infront of other clients is unacceptable because that attitude means that they do that because they feel that their positions give them some sort of superior authority over clients. That manner is unacceptable especially because it's their bread and butter but they choose to not respect their jobs. I do not want to be subjected to issues between stores which have nothing g to do with me as a client. Being shouted by people for no reason. Some of the staff at this store are very rude and we keep quiet because we do not want drama but this time I will not. The lady who was flaunting her position was shouting so loud when I was explaining to her that I was sent there by 1 of her colleagues. The disrespect at this store is over the top now.