Harassed by caterer

Sir we have a marriage in our family on December 1st week,from net we search and found a caterer details,then called him to met on october last week .On the day of meeting he explain about his firm and work,immediately asking for pay booking amount.I refused to give that and said i'll let you know after consulting with my family members,during our conversation in meeting, he asked about my father,mother,which place is my home in the city.On the next day he came to my home suddenly and insist a lot to give him booking amount cheque,we told him,we are not able to give the booking amount right now. Then he told me,you can give me the cheque of date October last date,but i'll drop it in my a/c whenever you able to pay next month.so i given him the post dated booking amount cheque.But from the day i given him the booking amount cheque,in every 3-4 days he asked me to give money.then after some days he asking about money very rudely.Many times without any reason he came to our house for money.so after see all these things we are really very harassed from him.so i called him and told that we don't want your catering service,then he immediately came to our home and starting threaten us that if you cancel the booking,you ll be in a big trouble. so this is the situation,sir please kindly tell us what should we do on this situation Thanks & Regards Chandan Tiriya Bhubaneswar