When your gift shop treats one as ********* or *******

I got a pair of shoes with my sisters as a gift but I wanted to change mine. I was turned back at the store because I had no slip. Everything else still in tact. Some shops like Ackerman and pep, etc. They exchange their things without a slip esp since it is gifts. Where even the price is teared off. But Rage refused to exchange their own goods because of a slip. So my sisters and I should share a slip so we can do exchanges individually and insist on a slip from the giver.