Truworths review: exchange of items

I am utterly disgusted in the manner how I was treated today. I went to exchange my clothes but was told that we cannot exchange the items with other items. Instead I was told by the store manager that they will keep the items I am interested in until I received my money for the items exchanged which was retuned to my card. Where is this contained in the Consumer Protection Act. I am a regular cash paying consumer and never did I encounter any such treatment.