automation tools

hi everyone!-quick problem:

working on a good quantity of files (hundreds)-need to change resolution to, lets say, 300 (vs 72 in the original file) -set up 100% for the scale- if I do it in "working on multiple files" :change resolution, scale 100, save in a different location-my files end up bad quality-pixelation, etc-the setting for the auto saving are lower (usually I save them manually at 12 quality) is there a way to change that?

thanks a lot in advance!