I made all that a little messy.

Scam = procedure, stratagem, scheme etc to defraud, steal, take money, goods, assets, away from people. Noun and verb.

Fleece = taking money, assets, goods etc improperly, immorally or illegally away from people, by what ever means.

Shafted for me usually means a large, significant amount of value stolen, withheld, not delivered , etc improperly immorally or illegally. Not just a days pay, but like life savings, or some years savings.