Sears Air Duct Cleaning Sears used to have such a good reputation Lorton Virginia

Truth in advertising. After reading many reviews and asking many companies about their cleaning practices, I selected Sears. The entire process took an hour and a half. They did not seal off the vents (as the phone contact led me to believe); therefore, in spite of a powerful truck-mounted vacuum, it doesn't suck - kind of like taking a vacuum hose, cutting holes in it, then trying to pick up dirt. After the job was done, they cut a hole above the blower and showed me that it needed to be cleaned which they would do for a company price of just $750, but if that sounded too high, the technician was willing to work with me and do it for a mere $250. Does this sound at all like a scam? I called Sears and asked to speak with a manager there and was told by a rather rude receptionist that the manager was in a meeting and couldn't be disturbed. I did not let them clean the motor. So I lost $215, and my system is not clean?