Yes don't trust your online transactions any where... you are giving your credit card details and if your credit card is stolen or used for some illegal activity it would take years to explain. Anyway when you buying currency online it does not matter if its based in Pakistan or online. cex.io is safe and very much trust worthy. Other two which i have used for fiat -> crypto are PyaBis and Coinmama. But CEX.IO is more preferable its UK based fully KYC compliance.