Faber — I wanted duplicate copy of invoice

Address:

Bangalore, Karnataka, 560060

I have mis-placed my invoice but have warranty card and purchase order, but i have missed my invoice, hence i have given all the details about when i have purchased the chimney, so that i can get a duplicate copy of invoice. But the owner of the shop is not even ready to listen about the situation and do the needful. I want to know how i should proceed so that i can duplicate of the invoice.