Not knowing the exact state of the power steering fluid in the first place, I would be hard pressed to tell you it was a scam. I'm sure they performed the service for which you paid, so at least that portion of it is not a scam.
With that said, you and everyone else should know, this is a typical way that places like Jiffy Lube (or other quick oil change places) do business. It's not that they tell the technicians to go out and scam the customer, but it happens because of how they setup the payment schedule for the technicians. This applies somewhat to service at dealerships as well. What happens is, if a technician (or mechanic at a dealership) spots a problem while performing the work you've asked them to do, they will bring it up to the service manager. The service manager brings it up to you. If you agree to do the extra service, the technician will get paid a higher percentage of this service as it is considered an "add-on" service. Because of this, they are always looking for ways to increase what they get paid, so may "sometimes" suggest services which you really don't need. If they can get you to buy it, though, they will get paid the higher amount. Service departments don't really monitor this too much as their gross income will be higher in the process, meaning they show a better bottom line.
If in the future you get this sort of suggestion to have a service done, go and get a second opinion, especially with a technician/mechanic you trust. This is the surest way to get only the services you need, without paying exorbitant amounts of money in the process.