I applied for citizenship in October 2015. In November, a change was made that meant I had to have a permanent residence card. I was rejected because of this. I feel this is extremely unfair!
Anyone else in a similar situation? Is it worth pursuing it? On my own or with legal advice?
My rejection letter arrived on April 3rd, and ever since then, I've been cursing my inability to understand the (reasonably clear) Booklet AN. The referendum gave me renewed determination though, and today I realised that there was a change that took place in November

"New immigration regulations came into force on 30 April 2006. If you are a national of a country which is a member state of the EEA or Switzerland, or the family member of such a person, you will automatically have permanent residence status after exercising EEA free movement rights in the UK for any continuous period of 5 years ending on or after 30 April 2006, and therefore will not have to apply for indefinite leave to remain."
...to...
"If you are a national of a country which is a member state of the EEA or Switzerland, or the
family member of such a person, you will automatically have permanent residence status
after exercising EEA free movement rights in the UK for any continuous period of 5 years
ending on or after 30 April 2006. You should apply for a permanent residence card to prove
that you hold that status before applying for citizenship."
How was I supposed to know this when I was filling in the application form in the months prior to November? I knew about an upcoming change to the language requirements in November, but not this. Even if I knew though, I wouldn't have thought it would apply retroactively for applications in progress! Is there precedent for this?
Aside from a confirmation letter (14th of November...), I heard nothing from the Home Office, until the 20th of February, when I received a letter asking me for “evidence that you were exercising treaty rights for a continuous period of 5 years…”. It went on to say: “Evidence should be from the earliest date while you were residing in the UK.” Such a requirement was not in any official document I had read! I found myself having to track down bank statements from 2001 (no way), medical insurance while I was a student (what? I didn’t know I had to have such documents back then!), and the acceptance letter from the university (which I haven’t kept). All I was able to send them was my university degree and a letter explaining the situation. This was seemingly ignored, and I was rejected in April. This time, the letter said: “…required to be free of immigration restrictions on the date of application… EEA nationals will be able to meet this requirement once they have obtained permanent residence…”.
Now I see that form NR (application for review) costs £272 and a fresh application would cost £1236! I don’t know what to do.

Any advice would be appreciated! Thanks!
Kind regards
Kostas