I got overcharged by vendor on old delhi railway station

Dear Experts,

I got overcharged on printed MRP by Amul Vendor in Old Delhi Railway Station premises, somehow I managed to get a copy of bill. I lodged a complaint immediately on Railway Complaint Tolll free No. 139 but complaint closed same day without contacting (which was promised during the process of lodging complaint).

My question is, who is the responsible party in this against whom a complaint in can be lodged in consumer forum?

1) It is Railway itself.

2) IRCTC who serves as catering partner, ticket booking partner for railway

3) The Amul Vendor itself

Thank you.

PS: Overcharging on railway platforms is a common issue, even though providing bill is mandatory now but still many are not providing and if you insist for it then they simply deny to sale their products or services to you.