Natiowide Bank / Is it true?

I do not know, where I can find confirmation, that the man (he have been writting to me since desember 2007) is real.
I received many letters and Nationwide Bank^s guarantee letter and Certificate of Incorporation from this man.
This is his adress:
Nationwide Bank Of England
1 Kings Park Road, Moulton Park,
Northampton NN3 6NW ,
London,England .
Nation Wide Bank Transfer Department
Chief Accounts Supervisor:Richard Bernard
PHONE:+[protected]
FAX:+[protected]
Email: service@nationwide.co.uk.tt
Bank Site:http://www2.onlinenationwidebk-uk.com

What I must do?