Their reply to my letter was-

" with regards to you request concerning that the account be closed and the balance returned to 0, please be aware that the effect of unenforcability under the CCA, and such enforcability we aver does not apply in this case, is to prevent a lender from enforcing the credit agreement in court. It does not render the credit agreement void.

While I understand this may not be the response you were hoping to receive, I trust I have now clarified the banks final position on this matter. "