What can I do after an illegal arrest?

I was pulled over with some friends. The police officer persistently accused me of having weed. I asked him what his evidence was and he responded that he could smell it. He asked if he could search my car and I said “no” because I had no weed. He went on to search my vehicle anyway and ransacked it looking for weed which of course he did not find. He found a butterfly knife I had bought the same day from a flea market for my collection. He took it and handcuffed me and put me in the back of the car and took me to jail without reading me my Miranda rights. I was charged with possession if a prohibited weapon. I do not think this was legal, what can I do?