Fashion Express return policy? All consumers *****

I wanted to return a boot my sister bought my mom without a slip and told them that I will accept a gift card so that my mom of 67 can buy something else at her leisure. The cashier said it is not allowed and she got another sales lady to go consult with the store manager. the sales lady appear wanting to know where I bought the boot and I rep**** that my sister did and I have no recollection. Then she rep**** and told me that she just want to verify whether th boot was bought. I then asked her very calmly to explain to me how we got hold of the boot if we didn't buy it. She 1st argued with me and when I told her that I'm not gonna leave it at that she called her Manager who then tried to explain to me that they need to verify as people do ***** and then want to refund. I was in retail for 18 yrs and cant remember how my and my staffs incompetence to protect our assets ever was the problem of the consumer. Complains on the Foshini group customer services also proven not to get any response thats why I feel that I don't have any other option as to expose them.