Puma — Extra vat charged on discounted product 10.5%

Address:

Thane, Maharashtra, 400607

Yesterday, i bought the shoes from puma (Thane ghodbunder) outlet. The shoe i bought was on discount of 40% on mrp. Rs 4, 299 (Inclusive of all taxes) but at the time of payment they charged me 10.5% extra vat. Charging of vat was nor mentioned in any in the store so before selling they should inform us.
According to the consumer goods act section 2 (D) any seller cannot charge extra vat on discounted prices. Because if we do than we are paying double tax on the product.
On asking questioning the shop keeper told us, it is government rule.