Mega Mart Retail Shop
Additional Taxes on MRP

I have purchased some ready made dress from Mega Mart, one of the reputed retails shop. Presently there they are offering the goods on a discounted rate and while prepare the bill, they will add VAT 4% on MRP (Discounted Price).

Could anybody can advise, is it allowed and if not can how/ where can i launch a complaint?

Rgds,

Ro