Elmo Data Supply Scammed me for toner, misled about price Los Angeles California

I get a call from this guy asking for the old administrative assistant.  I tell him that she is no longer here but I can help him.  He tells me that the old administrative assistant bought toner from him. 

He asked what type of copier/printer we had.  I told him.  He told me the price was "$619."  He then proceeds to tell me that someone from the shipping company will be calling me.

Not more than 2 minutes later the guy from the shipping company called and got the information he needed.

After the guy from the shipping company called, I got to thinking I realized that we get free toner from our printer/copier company.  I called the company to verify that.  They said all our toner  is included with our lease.

I had no number to call this person back at.  There was not a number on the caller ID.  He talked so fast that the only word from his company I could understand was "Elmer or Elmo."

I tried to go online to see if I could find anything about this company.  I knew the initials were EDS.  I still could not find out anything online.

I tried to stop the receiving clerk from accepting the package, but he was out the day it was deliveried.

We received the toner.  It had a number for the company.  I called and left my name and number.  A guy called me back.  He would not give me the address of where to send this back to.  He said we would have to pay a restocking fee.  I got so upset with him I hung-up.

A few days later we received a bill from them.  $678.88.  I about flipped.  I called that same day and received the address to return the toner.  I returned the toner.

I put a letter in the package that states "I am returning this toner because it was ordered under false prentense.  I was misled about the price of the toner.  Do not ever call or send anything else to (our company)  By the acceptance of this package you acknowledge that you will not call, fax, or mail anything to our office again."

If we receive a bill for the restocking, what should we do?  My boss does not want to pay this.  I told him the whole story.