Question about Oticon pro volume control

Hi, I have a pair of Oticon Pros for testing. This particular pair has a small squarish button on each unit for volume control - push the button on the right aid to increase volume on both units or push the button on the left aid to decrease volume on both units. Tonight I was going nuts because of the volume of extraneous noise in the kitchen while I was doing the dishes - water running, dishes and silverware clanking - almost unbearable. I pushed the button on the left aid until I heard the beep-beep-beep indicating it was at the lowest volume, BUT the right aid still seems to be at a higher volume. How do I get them to be both at the same volume? I think these units are going back to the audi before the end of my allotted trial time. Thanks. Joyce Keay