I got a friendly receptionist, and she told me a price by phone (depending on tank capacity) However the technician charged me 3 times that amount. And at the end they were very careless with their hose because it spread a lot of feces on my front yard. I won't use their service anymore. NOT RECOMMENDED!
The company has a cancellation policy which doesn't favor the travelers in the following way: Even if the cancellation was made on time is subject to owners approval which permit some abuse from them as holding the answer and the money for several weeks, or indefinitely.