Harassment at Cotton on

My daughter purchased 3 dresses from Cotton On and was told that it was on promotion. She went back to return one dress and wad then told by the manager that actually she had ****** the one dress as it was not on the receipt. They took the dress away from her and made her leave the store but on her receipt it was clear that she had paid for 3 dresses. Wen she went back to complain the manager and other employees shouted at her and harassed them in front of everyone whilst they left the store