Indian Railway Catering & Tourism Corporation [IRCTC] — travelling in super fast with express ticket

Address:

160101

I was traveling from Ambala to Chandighar
on 04/12/2018. I had express ticket and I was traveling in super fast train (Paschim Express).I had enquired at Ambala and he said the express train is coming. At chandighar railway station TTE checked the ticket and said you are traveling in super fast train with express ticket and will be penalized with a fine. He asked me to pay RS 300 as fine and on request he agreed on 200 not less than this.When I checked the fine receipt at home the littering charge is mentioned on the receipt.So I need to know is this the correct way to charge the fine of your choice.I should not be charged more than the ticket rate difference between express and super fast i.e RS 10 in this case.