Why should it charge extra for online payment thru means other than online banking ? Anyway this method is reducing their manual work of cash/cheque receipt, counting, accumulating & depositing it in bank, etc.
Though they are getting faster money with clerical work transferred to the consumer, still want to charge extra for online payment. Earlier, they even charged 10 Rs, extra on net-banking also.
Not moving well with the advancement in the technology in various fields it is associated with!