Exchanging goods becomes mission impossible!

Received a gift from @home - still in original packaging with barcode. Read their Ts and Cs on return policies. Went to the Rosebank JHB branch to exchange the item for a voucher and was told I need to pick an item now or take my product and leave with it. I walked around the store frazzled for a good 5 minutes because how do I pick an item on the spot?! I’m not sure if the Ts and Cs on the website need to be updated or changed but the store front definitely isn’t providing the same type of service on this.