My payment went through twice it was only meant to put £20 on but it’s got £40 how do I get that £20 back
Would it be possible you have two accounts, to prove this you need to look in your order history in your account.
Please click this link and scroll down to order history.... https://giffgaff.com/profile/payment-details
And look at what you have purchased in your account.
If there is only one £20 payment then the other must be the charge for another account, this could be a family member or possibly another sim that you activated in another account.
Sorry to hear about your problem. If you were charged twice, then you need to contact a giffgaff agent. These will have access to your account details and can process a refund, if at fault. Use this link https://support2.giffgaff.com/app/ask/Top-up-balances-and-goodybags/Credit-debit-card-or-PayPal-over... and explain your query clearly. giffgaff agents are very good and will help resolve this. Please note, they are not the people who are at fault, they are there to help, so please treat them with courtesy and respect, they are after, there to help you sort this out.
You may wish to check the order number for your credit added. This can be found here https://giffgaff.com/profile/payment-details#orders - you can then give the order number to the agent to help speed things up. Unfortunately any refund processed may take upto 7 days to return to the original payment source (depending on banks/card used).
By the way, if you use your credit for goodybags, you could always use the additional credit to buy another goodybag to queue for once a current goodybag ends. Guide here, if that interests you https://community.giffgaff.com/t5/Solve-your-questions/Guide-to-queued-goodybags/ta-p/3513321