Citing the model number would make your informational post more effective and helpful to people who read it later, for identifying the specific unit that is suffering the problem.

It sounds like it must be an older unit? You can try going to Home Depot or Lowe's and try to find a generic set of replacement knobs that might fit your KitchenAid range for an easy repair. You might come across a set that will fit perfectly and for half the price as getting it directly made from KitchenAid.