Family Dollar complaint: Very Rude Store Manager and would not return the product purchased

My daughter bought a pop-up tent about 5 days ago and it was very flimsy and was not appropriate for her daughter. When we went to return it in the original box (no receipt) the store manager made it clear that she was not going to allow the return. When I asked what the policy is for returning, she told me that it was at her discretion. She also stated that she doesn’t even know if she bought it or not. I asked if she was insinuating that my daughter stole it? I also asked what the rules and regulationspolicy and procedure are for returns, I was told to read what was taped to the counter by the register; however, it was unreadable because of the wear and tear. I was appalled with the disrespect arrogance of your Store Manager. I was asked to leave her store and she would not honor the return. I find it very hard to believe that she would have the right to make a return at her own discretion seeing that it can lead to discrimination based on her own beliefs.