Sathya Agencies — Not providing Invoice for Mixer purchased two years ago

Butterfly mixer was purchased in Sathya teo years back and unfortunately the product is kit working and it has a warranty of five years. We have the warranty card in hand sealed by satya agencies but unfortunately lost the hard copy of the bill. Since bill is mandatory to claim the warranty we approved satya agencies and they say that the bills/invoices are saved for only one year period. Do Satya agencies have a retention period of one year to the Bill's and invoices to the customer. Please guide us to get the Bill's for the same through which we can get the warranty claimed.