Amaron — my warranty card is lost

Address:

Bijnor, Uttar Pradesh, 246731

Dear sir/ madam
Mera warranty card kho gya hai or meri battery jo ki abhi warranty me hai sahi se kam nai kr rahi hai. Inverter on karte hi battery discharged ho jati hai. 5 minutes se bhi kam ka backup de rhi hai retailer k pass gye to bola k bina warranty card k kuch nai ho skta hai.
Please kuch btaye k battery ki kharabi ko kaise think kiya ja skta hai.
Thank you