sorry you are having trouble , i had a front sight off to the left on a mk11 gvt .22 , they sent me a new gun !
they do have mistakes get out , but they do a good job fixing them ( most of the time ) , anyway i had to get leupold rings on a mini 30 they were close to one side but zeroed !
i have a m-77 in .17 , 22 mag and .22 lr all have the factory rings and worked well !
if the scope fits in the rings , then the reciver is most likely stright ( it is injection moulded i think ) you may want to see if the bbl is stright in the reciever or bent ! maybe the socket for the bbl was drilled off center , might check the two screws that hold the bbl to the reciever , need same torque on both !
an after thought , check the lugs on the rings that index them on the reciever to see if any burrs are on them !
good luck !