I got the same from Barclays today. My other one with Close Brothers i enquired about in July 2023 so they are treating that as closed and i can take to the Financial Ombudsman Service which is how i found out about this at a quarterly meeting last year.Santander just replied saying;
We can confirm that a DCA was in place between us and the credit broker relating to your finance agreement
... so it's looking good for Christmas 2024.