Big State Industrial Rude, unprofessional collection process Riverside California

We purchase items from them occasionally which are then shipped to us.  For the last item received we had an outstanding bill, but I never received any voicemails from them.  (I would have gladly paid if I knew about the bill).  Instead, I got an extremely rude, unprofessional voicemail from a customer servce rep named "Westie" or something like that.  When I called her back, she was equally rude, so I asked for her manager who she said wasn't there.  I said I'd call back if she didn't transfer me, so she finally did.  The manager was more polite and reasonable, but I didn't get the feeling that she was concerned about the rep's treatment of their customers.  She also claimed that they had called and left voicemails previously although they hadn't.  We won't be doing any more business with them.  Ever.