Ada in North york

I had Weed Man served my lawn last year (2011). The service was not satisfactory and thus I decided not have its service this year. However, surprising, when I went home today, I saw Weed Man sign on my lawn and its invoice in my mailbox. I called to its customer service and told them that I had only ordered service for last year but not this year. I got a very rude reply that "we do need your confirmation. we will automatically service you and bill you. You must pay or we will send the file to collection agents." It is an absolute robbery. How can a company force un-ordered service on you to demand payment without even confirming to the customer first. I am going to file this to BBB. Everyone be alerted - DO NOT DEAL WITH WEED MAN OR YOU WILL GET RIPOFF.