NorthStar Alarm Systems charged for services not rendered. The Alarm System cannot work without a telephone line. I called to explain that the phone system had been disconnected because the property was vacant. They continued to bill because they said they received no notice of cancellation. I sent NorthStar an official notice of cancellation via regular mail and certified mail to cancel as of June 9, 2009. I paid them from September to June for the billing of $39.90 per month. They sent me a response indicating that although there wa... read full review »