Actually a company I worked for made a policy because so many employees (they Say) were being garnished and that it was costing them money to file the garnishments that if you get to you were to be terminated. Not sure if it was legal but it is true!

 Anything is possible.  i presume your wages are being garnished once a month.  this does not seem excessive.  if your employment is terminated because of said garnishment...i would contact my union or local labor board.