Sorry to hear you’ve been having problems.
I’ve only been with giffgaff about a year and any issues have been answered by the forum. However, I see frequent dissatisfaction from members who use Credit to buy data/calls etc and especially those who use Credit to buy a Goodybag.
I think giffgaff should give some thought to how these issues might be avoided.
The Goodybags themselves are very good, IMO, and straightforward if bought via a debit card. Unfortunately, buying via Credit can sometimes result in a few pence disappearing (due to background App activity) resulting in insufficient left in Credit to buy the intended Goodybag.
Best avoid Credit, if you can, IMO.