Big Bazaar / Futurebazaar / Future Retail / Hometown — Bajaj mixer grinder

Address: Big bazar woodsquare mall narendrapur kolkata-700103

I bought a bajaj mixer grinder gx8 on 26th january 2019.now i am having some issue with the mixer and now it needs to get repaired but as the big bazar bill ink gets erased within few days so now the.bill is of no use hence i needed a new bill but big bazar refused. Please help me to get the duplicate bill from big bazar so my mixer can be serviced within warranty period .
I bought it from woodsquare big bazar narendrapur kolkata.