I contacted Nutri Lawn (now known as GREENLAWN) to do a one time application for weed control which they did promptly. Over the next six months, they proceeded to hound me with weekly calls wanting me to agree to a contract, more applications, etc. I flat out said no and by the third month - told them to take me off their contact list which they never did.
They continued to hound me into the spring. One day my wife came home to find their truck blocking our driveway and told the Nutri Lawn employee to move it or it would be towed. She later realized they had done an application on our lawn and left a bill in the mailbox.
Having had enough, I filed a complaint with Service Alberta under the Consumer Protection Act stating that the actions taken by Nutri Lawn constituted a negative option contract and such contracts in Alberta are illegal. Nutri Lawn was ordered by the Alberta Government in 2011 to cease such practices.
Those experiencing the same issue with Nutri-Lawn can file a complaint with Service Alberta under the Fair Trading Act. For those who don't know, a negative option contract is where a vendor assumes that a contract is in place unless you act.