Railwire broadband bill pay in other site

Guys currently I am using railtel/railwire broadband service..it's kind of prepaid service where I need to recharge post plan expiry.. the problem is before expiry and after expiry even if I check in other 3rd party sites like Amazon, Paytm etc they always show the message no bill due ..only option for me to login to my railwire account and recharge from their and thus I am able to get any discount in the billing...anyone else facing same issue? How to recharge through 3rd party website?