STT CALCULATION

Recently i purchased 3 YES bank shares at 190.95 on 21/01/2019 and sold them at 219.20 on 24/01/2019 and STT charged is 38 rupees. May i know how this STT is calculated?

https://zerodha.com/brokerage-calculator

https://zerodha.com/charges

I had bought the bank nifty call at 13
Strike price :-28000
Settlement price :-28013
The problem is with stt.Nse have charged 21000 of Stt as per old rules.but this rule is changed from 1 sep .what should I do