I carry my Life Planner with me everywhere. It goes with me to and from school every single day. You can imagine the beating it takes. This picture shows the corner of my planner cover after a whole year of use! Notice the fraying at the edge of the cover. I contacted Erin Condren support to see if there was a way to fix this, and it turns out there is!
Here is the solution: Take a clothing iron (or straightening iron) set on low heat and seal the edges together. (Make sure you use cloth, such as a pillowcase, to protect your planner cover.) This works like a charm!
Note: When you iron over the teeth of the planner cover, they will melt together. If you re-seal the teeth, carefully cut them apart when they cool and replace your cover onto your planner.
I hope this helps! Happy planning!