Data Doctors Caution

I know of good experiences with Data Doctors, where they have rescued data from a crashed disk and diagnosed a boot-up problem as being due to a faulty power strip and nothing to do with the computer. But recently, I had them do their $59 "analysis" of a computer I feared was facing a hard-disk or memory failure. Their "analysis" showed no disk or memory problem, but reported 25 "infections," including 5 "critical" ones. Before taking in the computer, I had run multiple scans with multiple anti-malware programs and nothing showed up, so I was dubious. I was even more dubious when they said they could not tell me what the "infections" were, and conceded they might just be tracking cookies. And my dubiousness turned into downright disbelief when they quoted a charge of $249 to clean the machine and "justified" the charge on a misleading statement about what the "cleaning" involved (as if they were going to do some manual thing as opposed to just run a program). I asked for a refund. They chose not to.  It turns out I am not the only Data Doctor customer to have had this experience.