Misuse of VAT

Location/place: Panchkula

Name of company/service: United Color of Benetton

I bought a pair of shoes from UCB,Sec-8,Panchkula store of MRP 3299/- under the 50% Off Sale Period.
MRP 3299/- is inclusive of taxes but the store charged VAT of 13.13% again on the discounted price i.e 3299/2=1649.50+13.13%*1649.50=1866.08/-
Please help.