worst website to collect GST after discount

they are always behind GST charging on discounted price.

Suppose MRP Rs.1000
discount price Rs.600
then finally they will charge 600+12% gst
Final Price Rs.672
Final Discount Percentage 32.8%
if we apply coupon they wont give full discount.
MRP Rs.1000
discounted listed price Rs.650
apply 50% coupon then they will give only Rs.150 as discount not Rs.325
even their cancellation process also very worst
even their listed prices also high.
sometimes they cancel the order.