We're just members if the community we are unable to check the validity of your numbers.
A PUK number is for unlocking your handset when the password has been entered too many times.
A PAC number is for transferring your number from one network to another.
The fact that your previous network said it only last 30 days suggests that you do have PAC number which is good.
Please go to this link and see what it says. I would imagine that your first request didn't go through properly which is why it hasn't transferred.
Resubmit your PAC code and select a date for your number to transferhttps://giffgaff.com/support/ask