Refusal to exchange goods

I went to the Jumbo store in Goven Mbeki Port Elizabeth to exchange goods as these were items I received as gift during Christmas. Alll the items had their tags on and in the same condition - obviously I didn't have a slip as these were GIFTS. The manager blatantly refused to let me exchange them for something else, In the past I myself have spent so much monet at that store. Since that insident I havnt set foot in the store and I can assure you that you have lost a customer! So unless anyone can assist me further, it will remain as such. I'm sitting with these goods and all I want to do is exchange them for something else. I don't see hw this can be refused as in the past other stores have been more than willing to help. - no hassles.