Spice Jet Airlines — refund

I book my tickets for 30 nov 2017 in place of 30 oct 2017 by mistake. I request for refund but they cut airplane penalty by hige amount and refund me zero and for date change they are charging penalty that costs me too much. Airplines did not inform me about penalty and refund policy prior booking. I accept this is my mistake but charging this much for mistake is not a law