depends what system you are using.
pay on delivery is reliable as you can see the goods. It is being provided by shophive and daraz pk. You can search google.
Credit card system is not that much reliable in Pakistan as it can lead to fraud. We do not have paypal or ebay. But you can use VISA to get things from abroad.
Well you can also pay by easy paisa but I have not tried that.
Daraz is not reliable. I bought Samsung Galaxy S4 from daraz and believe me it was not a good experience. At the time they said that they will give me 3 months daraz warranty for the mobile. Upon receiving the phone I saw that although the box was in pin pack however on opening the box there were couple of issues with the phone. Firstly the user manuals were in different language. Then when I opened up the mobile to insert my sim card I saw major scratches on Sim Card casing and MicroSD Card Casing. Then when I started up the phone it would not connect to WIFI. After seeing these issues I checked the serial number on the box and it did not correspond to the Samsung Galaxy S4 meaning that the serial number was forged. I contacted daraz.pk and they replaced the phone with a three carrier Samsung Galaxy S4 phone (three carrier is telecom service provided in Ireland). After using the phone for 2 and half months, now a fully charged battery only last for 15-20mins and now daraz say that the phone does not have warranty.
Hope my experience helps you guys