Well I have two frozen pensions, one was a private one I was only paying £40 a month into for about 5 years.... Then I hit a rough patch and stopped it. The other was through my old company that got frozen when I got made redundant, that had about £25 a month paid into it for around 6 years.
I have just started this new one with my current job, I pay 4% of my monthly wage before tax, and my company match it, so 8% of my monthly earnings gets paid. So hopefully when I retire I may have a bit of cash to fall back on!