ive tried avout 4 times now to activate and top up with credit card. ive purchased a 10 pound goodie bag 4 times and each time after i press confirm purchase it takes to me to the page where i should be entering my credit card password or it should be confirmed. its just a white square with "YOUR CREDIT CARD" writedn in the top left. You can use a voucher instead of a credit card to top up the 10 needed to activate.  That's what people are suggesting. Have you looked at the thread that dearoldgranny linked to?  Could it be one of the problems listed in that thread?  If not then contact an agent and they will be able to tell you exactly why your card is being declined.  To contact an agent use the link on the left hand side of you My giffgaff page.