Hospital Records Query

Recently, I wrote to my local Health Board, requesting records of hospital stays etc. I can hardly remember a thing about these, for some reason. I had this response yesterday:

'Aneurin Bevan NHS University Health Board
WALES


Dear Sir,

I am writing in regards to your letter dated requesting copies of Health Records/X-Ray relating to the above named. Please note there were no records found relating to Health records due to you not being registered on our systems.

If we do not hear further from you we will be unable to proceed with your request.
If you have any queries please do not hesitate to contact us on: 01633 740167/740166
PLEASE QUOTE OUR REFERENCE NUMBER ON ALL CORRESPONDENCE.


Yours faithfully,
Access to Health Records Department
Online House
Cleppa Park
Newport
NP10 8BA'

It's definitely the right Board that I wrote to, by the way. Does anybody know what I should do next, if anything?