I believe that this is Tru Green in Daytona Beach Fl.
I left this company because of their deceptive sales calls.
It goes like this. We will be in the neighborhood and have you scheduled for such and such service and this call is to notify you that we will be by.
I think this is TruGreen too. I used them for a month or two last summer but their business practices left a lot to be desired. I ended it ASAP. They have tried following up with me several times, and I've told them every time to STOP CALLING ME IM NOT COMING BACK. To no avail, they just call from other numbers.
I'm not sure it's a "debt collector" because I don't owe them anything, but nothing would surprise me with them. I'll categorize it as a "telemarketer" call, although I think it's just a local salesman.
By the way, I'm not blaming this entirely on them, but since we used them, an entire patch of my front yard went dead last summer and now looks horrendous. It had been resodded in 2008 and was flourishing until last summer. Again, not sure it was them, but seems coincidental.