It sounds like you wanted to trade your ice cream dagger for a skull juggle, and it seems like you got it?
Then you wanted to trade the skull juggle for an umbrella or something...?
Anyway, doesn't sound like a scam to me and you said that you used the trade tables.
But I probably don't understand. However, scamming is still legal so there is really nothing you can do about it except learn from your mistakes and move on.