Product review (3 stars): Don't get rid of your dishwasher, fix the rack adjuster inexpensively
There are reviews that mention using a zip tie or epoxy or using a machine screw.

We run 3 loads a day.  I now have a box of broken rack adjusters, not counting the one replaced under warranty.  Just replaced another tonight, and have one more good spare.  I'll probably try the zip tie next, it sounds the easiest, and won't even have to take the adjuster off the top rack, which is always a pain.