Refusal to change size and bad attitude

Went to go and change my shoes which I bought last night tried then on at home and didnt fit they already had a few dirt marks on the shoes. The lady was so rude and wouldnt allow me to change my shoes and when I told her I baught the shoes like that she refused to change them never in my life have I been so disgusted in someone by the way she spoke to me and yelled at me. This is unacceptable!