We've used Wolff for years, our last annual contract with them for ac/heat checks ended, and we won't use them again. More expensive than competitors, and terrible customer service. Our last attempts at scheduling ended with a tech showing up 4 hours early, a tech not showing up at all, and a smart-alec phone rep who was unapologetic. I called last month to see if I could refund the remainder on the contract, the guy on the phone said 'no way, and if you wanted to it's above my pay grade.' I guess that means if the contract expires you lose tour pre-payment. There's far better companies doing it out there for less.