Hi,
There is a brand new service that allows PAYG users to call Pakistan for 6.5p/min and many other destinations including even UK Mobiles for less from any UK Pay as you go service (including Lebara and Lycamobile).
This is using a call back number that works with sms top up and is similar to Super Call.
The site is
http://www.textcallingcards.com/call-back.phpBasically you top up as normal by text to the shortcode and then when you are ready to call, dial the call back number and when it rings twice you will be disconnected. The system will call you straight back and you can enter thePakistan number and call your contact.
So its perfect for PAYG and people who have used up their free minutes as well.
The call back service will cost an extra 1.5p/min on top of the advertised rate to Pakistan of 5p/min.
Hope this helps.
Baz.