if the website is local you can buy from them on internet utilising the Top limit (not daily limit) of your card.
if it is purchased from abroad and shipped to Pakistan most likely chances are your goods will arrive with a customs demand note for release. The duty will be calculated over the amount mentioned on the invoice attached to the package.
if you decline to accept that and feel like claiming a refund form website they will send you a shipping note with a tracking number and arrival date at your customs. If you choose not to clear it their responsibility ENDs at customs.
you will lose more money if you try stopping credit card payment. That will lead to more trouble with credit information bureau of state bank.