SP+ Parking Fined for parking in Public Parking lot that had no sign with fees at entrance Nationwide

I traveled 2 hours to Columbus, OH to the food truck Fest only to be fined because I parked in a "public lot".

I drove around the event and looking for a safe lot to pull my car, I saw a "public lot" that seemed to be nice. There was no sign indicating payment as there was at some other lots, so I parked. Once done with the festivities for the evening I came back to find a orange envelope under my wiper.

The orange envelope contained a $30 dollar citation for not paying to park. The citation was not from the police but SP+ to which I filed an appeal on the included website just to be told I did not have a paid parking pass and the citation stands.

I agree I did not have the paid parking pass only because the was no posted sign, seem unscrupolus to me. Guess this is what I get for trying to support the local economy in Columbus.