How can i get max benefit of sbi cash back credit card for doing metro smartcard recharge?

[Subhajeet]

planning to go for recharging kolkata metro railway smart card no recharge option in amazon any way out to gain 5% using the sbi cash back card or any other card much appreciated? Please suggest. Thanks.

 

[metal_heart]

I buy amazon voucher from Gyftr & add to amazon and recharge DMRC card via amazon.

 

[Subhajeet]

its not dmrc its kolkata metro no such option available