Hi,
I would imagine you need to reverse one servo. I would hook one servo up to output A and see if it moves in the right direction. If so, unplug A and plug the other servo into B and see if it moves the right direction or needs to be reversed. If it needs reversing follow the instructions to reverse a servo. Then I would unplug B and plug A back in. Set your center and endpoints. Then plug B in and match it to A so that the servos are not buzzing.