The Salvation Army USA complaint: Just to make a exchange.i

I purchased a headboard and bed railings at one of your salvation army locations. The headboard is fine but the railings were too small. All i asked for is to be able to exchange the railings for the right size. My brother went to the store and purchased the railings. He misplaced the receipt. All i wanted was to get the size i needed. I do have my receipt for the headboard and I can just return the headboard but i would like to just be able to exchange the railings for the right size. I called the main office number and they told me all i will be able to do is just exchange them. Well that’s all i wanted to do and i dont understand why is it so hard after all it is used items. Maybe i would have done better getting new ones. But i would really appreciate it if i can get help to be able to do this. I would greatly appreciate it. After all i have been shopping at your stores for a long time now. Thank you very much.