Mis-Lead to buy product

I was called by Concentrated Solutions and offered a free 30 day trial product, after much persuasion by the gentleman I agreed to try out their product free of charge but before anything could be confirmed with them I asked the lady confirming our details to please email me this information so that we could verify what they were saying was infact true. I did not receive any email but see a few weeks later the products was delivered to our company . When I called Concentrated Solutions to fetch the products they refuse to accept it say that this is no free 30 day trial product as the volume they have given us is larger and blamed me for confirming the order saying that I have accepted it. I have sent numerous emails and made numerous telephone call without success. I see now they want us to pay a R500.00 cancellation fee.