Party City

I purchased a Halloween items (costume) and the person whom checked me out was not welcoming, rushed through the process, DID NOT mention any exceptions to the return policy and failed to send me an e-mail receipt even though I provided one. Now I was told that I'm not eligible to return the items because I don't have a receipt. Now I'm stuck with a costume that doesn't fit so I just wasted $40.
I'm very disappointed as I buy quite often at Party City for parties, holidays etc. I'll never go there again!