To answer your specific questions then:
1) Question:has there been a change in law?
Answer: There have been no relevant changes other than the law in 2006 (known as Pensions A- day)
http://www.talktalk.c...s/pensions-a-day.html
which included this change:
"Retirement age. The earliest age from which you can take an occupational pension or personal will increase from 50 to 55 by 2010. If your current pension contractually allows you to retire at 50, you will still be able to do so by 2010."
2) has there ever been a law that prevents you getting a frozen pension?
Answer- yes (see above)
So you should be able to access your pension (probably as a tax free lump sum plus income for life) before 65 if you want to, but if you want to leave until 65 that's fine.