Myntra.com — wrong billing amount

Today I ordered 2 T shirts from Myntra mobile app and while ordering T shirts and I got Rs. 966 as total amount but when I checked price details section the total amount was Rs. 965. Then I did all calculations manually and I found that the calculations are wrong. The bag discounts for 2 items are 527 and 427 and hence the total bag discount should be 954. But in price details section it is 946. What about the difference 954-946? Where Rs. 8 gone? And the total in price section is Rs. 965 but the amount deducted from my account is Rs. 966? Why Rs. 1 more?

And the height of Myntra is that they have changed the price of products after order is done.
Both before and after scrren shots are attached.