AJones:I am not especially worried by all this, but it has been dragging on for some time and would like it resolved. What should my next step be? And if it does go to court (a prospect I don't relish), do I have a case?
Do I have case? I presume you mean do you have a defence? From here, no, because the issue is largely self inflicted.
I am not especially worried by all this.
OK, your call but if you are asking for advice, my advice is don't scr*w your credit history for 6 years or more on a point of petulance.
In your case I advise the following. Settle.
Then do a £10 Subject Access Request with Natwest requiring provision of all your statements for all your accounts for the last six years, all correspondence, call logs, and telephone recordings. Good value for £10.
Submit a formal request for repayment of all "unfair" charges using a reclaiming charges template letter. That's it. As you have already been informed processing is on hold. Some day it won't be and possibly you may get lucky.
This is a completely different issue from whether it was right or not to levy the charges. Normally I would advise the Financial Ombudsman Service route. Up to you but I believe the FOS will not look kindly on "petulance".