Big Bazaar / Futurebazaar / Future Retail / Hometown — need duplicate bill

Address: 711103

I purchased 51 bar one cadberry where 27 were 5/- and 24 were 10/- but the guy in counter placed 10/- for all. I had purchased other items too in that bill. Fortunately i got the refund of 136 /- from customer care for chocolates but they marked in the original bill which i suppose to submit in my office for claim purpose. I asked a duplicate bill but they denied. Please provide a duplicate bill for the same. Shop located at avani mall shibpur howrah. I have attached the bill