Payment sometimes diverts to a card that isn’t mine - possibly a family organisers

So I’m currently out of the country on a trip but will return soon. I’ve been trying to buy some more games for the plane trip. My debit card is the default - and only available - card in my Apple wallet but on payment it directs me to a « manage payments » screen where I need to verify the details of a card that isn’t mine. I suspect this is the card of my mum - who’s my family organiser - but I have no way of removing the card as a default payment method because the card was never saved on my device to begin with. Is there a way to get around this payment method without being removed from the family?