On the spot, ask for a supervisor (if you look at the Officer's arm, you will see that her uniform had 1, 2 or 3 stripes and she was likely a 1 or possibly a 2). Just stand there until the supervisor comes over. Make your case and then proceed. As others note, just be polite and don't get into a fight about it.
If the supervisor goes your way, off you go.
If the supervisor doesn't, file the complaint. Try to find the same product and include a photo or an exact description. Stick to the facts.