At the start of the cartoon (even before the main theme song), Hank is looking for batteries at Mega Lo Mart and is having difficulties getting any of the employees to help him. As one of the teenage employees says "Right through that door, sir" (thus pulling a prank on Hank by sending him outside), the sign above the shelf reads "Save Big at MegaNO!"
Bobby said that the tissue box didn't come from Mega Lo Mart but was touching something that was, even though the tissue box clearly says "Mega Lo" on it (though he may have just been testing his father's patience.)