The one year I had them, I had to call them out three times for a single service. Now you might expect that it just didn't do anything to my lawn, and I needed a re-spraying, but no... I get a bill in the mail, but I never got those little signs in the lawn or the invoice on my door. They went a block over and sprayed someone else's yard. And the best part is that it happened more than once. When I was on the phone complaining, they told me that they must have written down the wrong street, but seemed thoroughly confused when I asked how they seemed to have gotten the right billing address. I don't know how some people remember how to breathe.
But I was able to get out of that contract because they were obviously not fulfilling their end of the obligation. That and I threatened a lawsuit.
