I remember a post on the QVC US forum about someone getting the returning too much. A woman replied saying she worked for Macy's department store and had a number of women very wealthy who had their accounts closed for too many returns. Social event coming up and they came in bought and returned the day after. She said stores do keep records of returns and it is so easy now people use credit/debit or store cards.
Now, this is interesting but in the US you can buy cosmetics use and return no questions asked some without the packaging. Here in the UK they usually only do it if a reaction to the product. I think Estee Lauder do accept returns for other reasons. I read all the time on the forums, "oh I bought and just did not like the colour on me and brought it back." Many places take back without a receipt though that seems to be stopping and even Ultra you need a receipt. I asked a friend who worked for YSL at the time about returns in the UK? She said if they did it then the prices would go up to make sure the companies did not start losing money.