, brace yourself for a lack of sympathy. I'm not saying any of this to be mean.
On what grounds are you contesting this? You knew you weren't supposed to block the tracks so it's not like you weren't aware of the law or disagree with it even. Pay the ticket and next time be more careful and don't pull forward unless there's enough room for your car to clear the tracks. It's for your safety, the safety of everyone around you, and those on the train. Just don't block train tracks ever again.