Non Payment of Credit Note

Location/place: Gurgaon

Name of company/service: Unicon Real Estate / Real Estate Agent

I have purchased a property through Unicon Real Estate and was promised a discount in the form of credit note from this company, which I was eligible to get cashed after I make 30% of the Payment of the Property. I have already paid 50% of the amount and I have tried multiple times visiting their offices in Noida and Gurgaon but they are not ready to pay.