Big Bazaar / Futurebazaar / Future Retail / Hometown — brand factory

Address:

500081

Hi just want to know is is correct to charge gst over the mrp. As i had the word with the person on billing counter, he replied that in brand factory our billing procedure is that we will charge gst on every discounted product. This happened with me the product was initially for 799/- after discount it was for 599/- while billing gst was added to it so i had to pay 628.95/- which includes 5% gst. According to the indian government mrp includes gst, thus the discount is on the mrp thus the gst is not applicable on the discount price too... I might be wrong as well so just want the clarity on this.