that is what a supervisor is there for, to make sure the IO is doing his job correctly. Supervisor was a woman, she didn't even come near me, just came out a room yelling stuff from far away. The reality is they are untrained unprofesional people, neither the IO neither the supervisor were able to communicate, dude was asking me questions using google translate lol
I wouldn't try brive police to clear the ban, specially if you are not savy enough (based on you being scammed already with the visa), you might end up in a much bigger problem. If you have evidence of you being scammed you could go to the tourist police and let them know you have been victim of a scam and you are leaving the country