Proactive Solutions Payment Demand for product I do not have ! Des Moines, Iowa

ProActive did not work for me.  They sent me the monthly shipment with the bill.  I took the box - completely intact and unopened - to the post office and asked them to please return it to sender.  The lady at the post office said everything looked fine, and accepted the box of product and said it would go right out.  She did not give me any kind of receipt.  I thought everything was taken care of.  Weeks later I began getting nasty "demand for payment" letters from Proactive. I wrote on the invoices that the product had been returned, unopened.  I got a letter from proactive threatening to turn me in for collection.  I CALLED them this time to straighten it out. The guy said I owed them the money.  I told him that I didn't have the product.  He checked and verified that Proactive did, indeed, receive the product and had it in house.  But, he said, I STILL owed them the money for it.  I said "Why would I ever pay for something I don't have?"  Today I got a letter from a collection agency demanding payment.  For a product that I returned unopened and do not have.  Now, really, what is wrong with this company.  If you see an ad for Proactive - RUN as quickly as you can, the other way.  Bad company, bad customer service, bad bad bad.  Don't get involved with them, tell everyone you know.