Denial of Incentives without prior information during resignation acceptance

Dear Sir / Ma'am, I recently quit an international hotel brand. I work in sales, so a part of my pay comes from my incentive that is calculated from my over achievement of target offered. When I put down my request of resignation I was verbally assured that I would get my incentive in my final cheque. However, once I received my final cheque, I was being denied my incentive saying that a policy says that an employee would not receive his / her incentive in case they decide to quit during the payout. There was no prior intimation that was initiated by the hotel to inform me that I would be denied my incentive during my resignation acceptance. Another Issue that I faced was with my notice period. They earlier confirmed a one month notice period, however, on finding my replacement and ensuring that the handover process was a smooth one, a special permission was taken from my department heads that I would be allowed to leave 5 days prior. But, the Hotel never mentioned to me that the 5 days would be charged to me which again was highlighted by me when I received my final cheque. Please do advice if there is any legal way around this. Do contact me at [deleted] for your feedback. Thanks! Hrishikesh Kaikini