Pleasedo no not worry, you can ask for a refund here, fill lout the form and an agent will get back to you.
Replies are found here
Hi @kayty20 You will need to contact agent online for refund 1p https://support2.giffgaff.com/app/ask/Top-up-balances-and-goodybags/goodybag-allowances-or-credit-ba...
Agent will respond here
I topped up my phone with a £10 voucher and £15 voucher and it only gave me £24.99 I always get the £25 goody bag but this time it took 1pence if me and I don’t know why so it stopped me from getting my goody bag
There's no need to buy £10 + £15 giffgaff vouchers, just ask for O2 vouchers because
giffgaff accepts O2 vouchers, these come in the following denominations: £10, £15, £20, £25, £30, £35 and £50.
you can apply the voucher online or call 43430 or 4444 from your phone (free call) seems an error has occurred and 1p has been deducted, the agent will refund that so you can purchase the goodybag you want (try not to use your phone/mobile data on the meantime (a bit inconvenient I know) to avoid losing your credit) the agents can be messaged here
Direct link to ask an agent:
Please note: Our agents aim to answer all enquiries within 24 hours. Replies from our agents can be read and responded to from https://giffgaff.com/support/questions