The natural choice turf shop

I used this company 3 years ago for the season and all was normal. Two years ago they started coming and leaving invoices. I caught them at the 2nd or 3rd service and asked them to stop and paid for the services rendered until that point. Then last year I was out of town for 7 months due to work. Apparently they came again and did some work on my yard because Phil, the owner, just called me looking for $150. I’m looking for guidance on how to deal with this because this service was absolutelty unsolicited and I consider it an abuse on their part.