dude.. you don't understand the point here. It is YOU who made the trade, not Zerodha. If they told you to do also, are you so dumb to do whatever anybody says ?? If yes, you should nt be trading at all in the first hand.
Accept the mistake and try to learn.. that is how a trader is made. not by blaming someone else.
Regarding order execution, orders are executed automatically. Do you think zerodha constantly monitors your account and changes the order which you made ? heck they wouldn't even have time to see who is placing what orders. Try to get your facts right. In market, order slippages always happen. By the time you click modify and edit the order, it may be some 5 to 6 seconds, during which there is all the probability in the world that the price slipped from 231.8 to 231.3 and your order executed and the price went back to 232.
There is no use blaming the broker. Trade with your preparation, not because someone asked you to. period.