This won't help your bolts that are already rusted, but let's look at prevention:
Do you let your refrigerator dry out when you store it away? If you leave the doors open after you turn it off, there is condensed moisture, especially in the freezer. I leave mine open overnight, wipe out the water I can, and leave the doors open until the next time I check it.
At that point, inside the door latch handle is a small tab that you can engage, keeping the doors open just a small amount.
Bad decisions make great stories!