Think you need serious legal advice as an onerous contract IF it is as you decrcibe is likely unenforceable because there is no benefit to you.
The worse factor is new employees joining either get or don't get the job by signing up to a pension scheme that they will most likely not get (exclude DAA staff from that one), which is very upsetting for those staff. I really don't want to give out much more information because its pretty reckless of me to do that, but let me just say this racedo, do you not really think if all of us could get out of IASS now while we can we would? legally we can't.