Hi Chicwithknives,
The first thing I would check is the bearings on the bottom door hinge.
If they worn out then the door will never close properly.
Also you can adjust the door, using the upper door hinge.
The magnets are inside the door seal and do not sold separately.
- The part number for the bearing (bottom) is
AP2113416
- Here are the break down diagrams for the Frigidaire freezer
Model MFU12M0GW0
Good luck.
Gene.