Ulta Beauty review: returns

A week ago, my friend (who doesnt shop at ulta or sephora) bought a Perricone MD product for my birthday and stupidly (ill admit) didn't request a receipt or a gift receipt. I requested to exchange said item for another as the boxes look pretty similar an employee with short dark hair named Karlee ? (employee) told me I couldn't exchange it because she didn't know if I had purchased it there and I had another return with a receipt, she accepted that one but not the other one and told me "Sorry! Have a nice day!" I was humiliated because the other customers looked at me as if I had stole it and tried to return it! I am a diamond member, i have the money to buy from you! Why would I steal it? I looked to see if there is a policy with those because i thought i was in the wrong and there is a policy for return without validation and thats store credit.