How do you get out of seat belt ticket when I was wearing my seat belt?

Well, you can't "get out" of any ticket that you have been issued. The officer who issued the ticket is accusing you of committing the infraction for which he issued the ticket. If you feel that you did not commit the infraction, then you have the right to take the matter to court and fight it. It's the same thing as if you were stopped and given a ticket for running a stop sign: it's your Word against the officer's. The question that the court will ask you in a defense like this is: why would the officer stop you and issue you a ticket for not wearing a seatbelt if you were wearing one.