Indian Railway Catering & Tourism Corporation [IRCTC] — tea /coffee

Address:

Raigad, Maharashtra, 400104

I travelled on train 12449 from ratnagiri to bsr on 11/02/20, i took 2 coffee, which was served by pantry car staff on the train, suppose to be rupee10.00 for 150 ml as per rate list in the pantry car, but the server asked me for rupee 30.00., and he served approx 100ml of coffee it was not 150 ml. Aftewr i finished my coffee, i noticed the rate of coffee for 150 ml is mentioned as rupee 10.00. So when he was returning to pantry car i asked him about charging more and giving less quantity of coffee, he said there are two types of coffee, and he gave me rupee 15.00 wala coffee.
First of all he never mentioned that he has two types of coffee or two types of tea, one for 10, other one is for 15., since it is not listed in rate list in pantry car two different types of coffee with two different rates. And i have observed that this is common practice of charging more for the product and giving less quantity all the time, this is clearly cheating, i guess people don't have time to report or want to deal with this kind of problem.
When i went to talk to pantry car manager, i got my rupee 10 back for charging extra also i made sure that he provide me extra coffee for serving less quantity in first instance, he gave me receipt, which was legal for the price and quantity. I am sure he would not have given me receipt for rupee 15 for 100 ml coffee.in fact server was arguing and manager was supporting him that he had given 150 ml of coffee for special coffee which he charged me rupee 15.00.
I am sure everyday this pantry car staff must be making lots of money by charging extra and serving less quantity. Of tea/coffee with full support of manager in charge on the pantry car.
How can this be stopped? I know it is just small amount of rupee 5 for tea/coffee + getting less quantity for a cup of tea/coffee. Millions of passengers travel everyday on indian railway and this is common practice of cheating is on.
Hope there will be some strict rule comes in to effect so people don't have to pay more, in fact they can get better product for the price they pay if there is no cheating involve.