If you based your pension expectations on 'estimated' future earnings, you were rather rash to have done so. My financial estimates were always based on the present, rather than on the expectation of future salary levels.
Your income has not been 'cut', it has been frozen. There will be a relatively small de facto impact due to external factors, but you have not had a significant cut to your present situation. Whereas those on overseas postings most assuredly have.
An example of the mean attitude of MoD was the way a colleague was treated when he PVR'd whilst in the US. By virtue of his status, he was normally entitled to a premium economy flight back to the UK. But his flight home was 2 hours after his exit date, so he was only permitted a cattle class seat.... If that's the way they treat 1-stars, what hope is there for anyone else?