i forgot are 0808 numbers part of goodybag minutes
They are completely free so no credit or goodybag is required to use them.
So you could just get a £10 top up to activate and never spend any more for the free calls (unlike the free giffgaff calls and texts which require a top up every 3 months).
Im sure theyve used ny minutes :/ will have to keep an eye on it next time I call one haha
Certainly they shouldn't have used your mins but maybe you called an 08 number that wasn't 0800 or 0808 and used 0845 or 0870 which would use credit or weq4u app which uses mins.
If you have the weq4u app that automatically uses your mins instead if directly calling those free numbers if you have it set to automatic.
I got caught out by this and now have it switched it to manual.