Yeah, there have been reports from this on FT many times before, you're not the first nor the last.
About the "scam" aspect, that's very debatable. You could've contacted the airline directly to provide a service free of charge, however, you voluntarily (no one forced you, no one) contacted a middleman to do this for you. They disclosed the fee to assist you beforehand, you agreed to the terms, gave your credit card number, they delivered said service, and they charged the agreed price. You most likely saved valuable time by not having to wait in the airline phone queue, and that could be a lot of time nowadays. So how exactly did they scam you?
Based on other reports on FT, it also appears that these companies don't impersonate any of the airlines. They won't use their logo, nor would they answer a call with, say, "United Airlines", rather they answer with a generic "Reservations" or "Ticket support". Although some reports claim otherwise, they seem to be careful enough to not make any false claims during the ensuing phone call. However, they are pretty good at bidding on Google AdWords to make sure their phone number pops up at the top of a relevant search, and Google happily rakes in the money and makes sure they are at the top. This has been going on for long enough for Google to be undoubtedly aware of this, yet they chose to continue to enable this practice.
Scam? I don't think so. Deceptive? Yes, but only because you rightfully trusted Google to provide you with the correct phone number, while in reality, they will provide you any phone number that some paying third party wants you to see. That's because Google doesn't care about you, it cares about those who pay for ads. Without Google's helpful assistance, these practices wouldn't exist.