I suggest you try clearing your browser cache and history or use another browser e.g Google Chrome, Mozilla Firefox, Safari and then try again. If still no joy then i suggest you raise this with a agent to investigate. As this doesn't fall under any category when asking a agent please follow this link https://giffgaff.com/support/ask/sim_my_limit_increase select 30 from the select menu and then write your question in the text area provided. Please provide as much information as you can on the issue .
please note agents may take up to 24 hrs to reply to any queries.