As someone who reaches State Retirement Age in approximately 32 hours one has to query why it has taken some 32 Years for this problem to come to light.
Moreover, "National Insurance" is a deduction from income decided by HMG over which the Payee has no control. This money was not withheld by the Payee, it was failure to collect the money by the Government Agency whose duty it was to do so.
This does not surprise me as I recently received a letter from the Pensions Agency in respect of my State Pension which detailed 5 different Schemes that I had been in (and which I knew nothing about) - one of these Schemes will provide me with an extra 1 Penny a week (before Tax).