Firstly, you need to be aware that GoodyBag free minutes cover calls to UK mobiles (usually 07 numbers but please note that numbers beginning 070 and 076 are not mobile numbers) and landlines (numbers beginning 01, 02 or 03). Outside GoodyBag allowance, calls to these numbers cost 15p/min.
Calls to numbers beginning 084 and 087 cost at least 25p/min plus a service charge set by the organisation being called.
Calls to 0800 and 0808 numbers are free; they cost nothing and do not use minutes from your GoodyBag allowance.
You can find more information on pricing at http://giffgaff.com/index/pricing
If the above doesn't apply to you, you can check the number of minutes currently on any GoodyBag that may or may not be active on your account by dialling 1007# from your handset.
If you find that this reports zero minutes (or some other unusual value) in relation to the GoodyBag you believe should be currently active, then first check the payment history on your MyGiffGaff page at https://giffgaff.com/orders/history and make sure everything appears as you think it should, and if that shows that your purchase went through, then you'll need to contact an Agent, which you can do at https://support2.giffgaff.com/app/ask/Top-up-balances-and-goodybags/goodybag-allowances-or-credit-balance-incorrect/form/
Agent replies can take up to 24 hours, however, they're usually much quicker than that. You'll find any Agent replies at https://giffgaff.com/support/questions (you should also get an e-mail when a message is received there).
GoodyBag texts cover messages sent to UK mobile numbers, meaning that international texts, or messages to short code numbers are not included, and usually charged from airtime credit.
If you know that's not the case, you can confirm that you have a text allowance remaining by dialling 1005# although you should note that if you have unlimited texts will display as 0 with no expiry date)
Additionally, a single text message usually can only be up to 160 characters length, and while many handsets will allow the sending of a text that is up to 480 characters by breaking it into three separate messages, anything over that would be sent as MMS, and thus would be charged accordingly as MMS messages are not included in any GoodyBag allowances; they require airtime credit. In addition to this, some handsets run software that converts smileys into pictures, which mean they require an MMS to send.
If none of the above seem to be appropriate, you should contact an Agent at https://support2.giffgaff.com/app/ask/Top-up-balances-and-goodybags/goodybag-allowances-or-credit-balance-incorrect/form/ They will be able to explain why the charges have been made and/or organise a refund where appropriate.