Just one more thought if you are still having problems with the scope.
Take it off and put it on another rifle altogether and sight in with that rifle.
If it sights in on another rifle without any problems the issue will be 99% of the time with the first rifle and or scope bases/rings.
If it turns out to be the scope, I think that getting factory service or replacement will be no problem. I have heard good things about the resurrected Redfield brand of scopes.
NRA & NAHC Life Member