Indian Railway Catering & Tourism Corporation [IRCTC] — complaint about irctc food plaza at jaipur junction platform no 1

When i went to the irctc food plaza and asked cashier for a normal plate he told me to give change by saying that he doesn't have change for 500 rs. I waited there for some time to let him having change for 500 rs and i saw him to have change for 500 even he did not gave tocken for plate and then after some time when an uncle came there he gave him change of 500 rs. When i asked about this partiality he replied uncle is having total bill of 132 rs but you have bill of only 85 rs. I thought railway is having first come first served but it is just depend upon your bill to be served first.