Refused to give me my money back

The manager at baby city carnival mall does not have manners she doesn't respect and doesn't know how to speak to customers. I bought a toilet trainer on the 19/12/2015 and I returned it on the 20/12/2015 wanted to exchange it for something less instead of give me my refund from the remaining balance she refused. I won't buy there again TEACH THE MANAGER MANNERS