not surprised with there reply to you, most of them guns of that nature are , set to a 7 yard group , not 25
so I am gathering if you shoot it at there 7 yard deal, it will be closer to point of aim and thus, NOT what they would warranty
not any help on fixing things, just passing info on I know from dealing with them and many other OEM's over the decades!
as for a fix, I gather you coudl MAYBE file the side of the sight to help adjust things a little?
but like many fixed sight guns, your kind a stuck with what they are and have to just learn to compensate when aiming knowing where they shoot!!