Not Exchanging Goods

I purchased a pair of slops at Spar (Lakeside) I then went to Spar (5Ways Mall) to exchange them, on the same day, because they had the colour I wanted in the size I needed. I was told by one of the managers that the owner said they are not allowed to exchange goods purchased at another Spar. He suggested I go back to Lakeside (which is in Richards Bay) and get my money back then go back to 5Ways Mall Spar to buy the slops. This is outrageous. As a customer, I don't feel like I should be put out because of insuffiecnt stock at either Spar. I am very unhappy with the way I was treated and spoken to at 5Ways Mall Spar and think the suggestion I was given (as opposed to just being able to swap the slops) is ridiculous. I would still like to exchange the slops and will not wear the ones I own currently, I am unable to go back to Lakeside as I live in Empangeni.