Paying for my own iCloud storage whilst being part of a Family plan owned by someone else

I have had a subscription to iCloud storage for some time, and have recently joined a Family plan. I understand that I can choose to keep my iCloud storage plan rather than join the family storage -- which is what I have done.

However, the direct debit has now been transferred to the Family plan owner, who is now paying for two plans (the family storage and my own). I cannot see an option to pay Apple directly for my storage plan; under iCloud > Payments & Shipping, the family plan owner's card is there, cannot be removed, and the option to add a payment card is greyed out.

Is there any way around this?