Hi
@johnrclarke
You just fill in this form and then giffgaff will get a PUK code for you, usually within 24 hours.
It's usually easy and you literally just type it in the phone, but if you have a complicated phone then Google and download your phones instructions manual and read it while you are waiting for giffgaff to get you the code.
https://support2.giffgaff.com/app/ask/SIM-and-number/Getting-a-PUK-PUK2-code/form/