Activations are much lower the last few month due to the current lockdown situation.
Its worth remembering that once you become a Super Recruiter, you do not get payback for the Activations Its important that you try to aim your recruiting at people who are likely to stay with giffgaff and top-up again.
It is not easy to get shop owners to stock other people’s SIMs. It may be easier if you already have some kind of friendship with the owner. eg your local barbers (once they are open again) may be happy to stock some.
Best of luck.