I speak as an LGPS pensions clerk (for the past 15 months) and union rep (for the three years before that).
Someone choosing to retire from the LGPS at 60, when their 'normal retirement age' is 65, would indeed have exactly the reductions you quote.
In your situation it is extremely doubtful the retirement is voluntary.
If you were made redundant at 60, there would be no actuarial reduction. You still wouldn't have accumulated as much pension as if you retired at 65, but that's a different thing.
It's not redundancy - the post still exists - but neither is it voluntary. Was there anything in writing to the effect of 'the postholder agrees to retire at 60'? Certainly if anyone had come to me as a rep in a situation like that I'd've taken the case, but it would have needed a specialist and would quite possibly have gone further up the line.
Hope that's helpful - best wishes, Steve.