Pathetic service, embarrassing to say the least

I received a Salomon Bonatti WP jacket men's size medium for my birthday as a gift. I tried it on and its way too big one size down would be ideal but I could not complain to the person who bought it for me all the said it was bought at Cape Union Mart as they only shopping there for great service and excellent prices. So I couldn't ask for the slip too. Anyway I asked my wife to go to the Canal Walk branch not sure which one inside or outside. Anyway she went in store and told one of the sales consultants that all she wants is to exchange for one size smaller not for a refund at all. The item is brand new never been worn as it's too big. The consultant politely said she can't exchange without a receipt the more my wife said it was a gift and she doesn't want the money back it was purchased from Cape Union Mart, but because it's a gift the receipt was not given I mean seriously who gives a receipt with a birthday gift for all to see what the person paid for the gift. My wife got so upset that she stormed out of there so flustered and said I must rather go myself and explain as the sales consultants wasn't very helpful. How embarrassing that must of been it's not like she stole the item it's brand new and she said it was a birthday gift for her husband. We don't want any refund just one size smaller that is all. I see you guys have a size small online in stock. Please help us this is really the first time we experience such bad customer service from such a store and we purchase regularly at the Cape Union Mart stores.