Want to exchange the product

Last time i called the avon customer service to tell them the foundation that my client orderded was her shade ,they told me to give it to my sales leader ,i contacted her and she said she does not know how to return the products, But i saw my invoice paper there is a place to return and adjust product,can't i give the product to the courier guy who deliver my orders? Because am loosing my money with products that need to be exchanged. I can t call the customer service because they don't help