I also wish we could use some of our available credit to make a donation to this great charity offer. Doesn't matter if we get credits or kudos in return, just let us use what's part of already a credit in our account to make a donation. Money's already there, is it so hard to use part of it for this great cause? Even Paypal could work if needed, to save us having to use a credit card, with all the security issues that might incur.
EDIT: Several years ago I suggested that part of giffgaff's Payback be split, where we could then use a part of the Charity Donation section to fund a charity, without all of the larger amount also getting applied. Many members disagreed with my suggestion then, as they might now, and it went no farther. giffgaff said at the time that they couldn't implement that, so nothing was done. Still might work, if giffgaff could find a way to make it happen. June is almost here, with it's 6 month PB coming at us.