Ok, sorry for going back and forth on this...
I emailed Amazon this morning about the $219.94 charge, which was the
original price of the combo set. They emailed me back and said they
researched my order and that the $100 discount was applied to the order
and hasn't been charged yet. The $219.94 was for the Forrest DadoKing
set I had ordered a couple of days ago, which happened to equal the
exact same amount as the combo kit's original price. So I was simply
mistaken. Amazon said they assure me that the $100 discount was
applied, so it does look like it went through.