UNFAIR TREATMENT

I sent someone yesterday 03/11/2022 at Exact Brits to do an exchange for me.,i had 3 items to exchange..I misplaced the 3rd receipt but did not want money I only wanted to change for another size Yooooo Exact staff members showed us flames,they did not want to exchange..I mean I did not want cash only exchange but they refused So my question is since I don't have a receipt I won't be assisted??So what must happen to the item?