Complaint Review: Suzuki Corporation

I took over a small teaching studio.  There were 3 new, Suzuki digital piano that never worked correctly, so I sent them, Nov. 2007, back to Suzuki in CA. 
The first service rep, Ron, said he would trade 2 of the pianos for 1 new piano.  I agreed to that deal.  He said they would repair or send a refurbished one for my 3rd piano.
That was 4 years ago.  I have placed numerous phone calls to all their service reps since 2007, Ron, David Stroka, M. Rodriquez.  No one ever took care of the problem.
The present service rep, Matt Harpster, never returner a call.  I only spoke to him when I called and he happened to answer the phone. 
In our first conversation, he said he'd look into it.  Never heard from him.  The second conversation...it was too long ago and they no longer had any records.  That was Suzuki's fault, they lost my pianos and covered it up.  Third conversation, he used the words misunderstanding and miscommunication.  Our last conversation he said they sent the pianos.  Show me where they are!!! 
In 4 years, I have lost $$,$$$ in lessons and pianos.  This is my livelyhood!!!  This is all because Mr. Harpster and his co-workers could not say, "sorry, we lost your pianos, here are refurbished ones in place of your new ones you sent us to repair."
I need my/any pianos as not to lose my business.