Never buy anyone a gift from jet

So yesterday went to Jet N1 city To exchange a item that my child got as a birthday present. Wanting a bigger size... Told the jet staff member that was by the door and was told that I can't exchange the item without a receipt because of their new system which requires the slip.

I went out with the item.. I don't know what I'm supposed to do with it now because it doesn't fit my child

I'll never set foot again there... I'm ****ed