I speak from experience, do you have much longer before you can retire , 40 yrs service in one job is a long time, and I get that you are angry of your situation.
I retired early ,from the Mail, always was the aim when I started in the Post office , pay of mortgage and retire at 60, that was the terms when I joined, I managed to go 4 yrs before that, mainly coz I was being 'Tittted ' around, they wouldn't give me Voluntary retirement , so I weighed up my options and left, very satisfying handing my notice , then telling the depot manager I was going, he said I didn't know you were serious about it!, that was 3 days before! They had my notice a month!
The point is, it becomes tax efficient to go early, if your approaching retirement , your not actually putting any more into your pension, if you have a occupational one, private plans are maybe different, but my Tax income is almost Zero, so I actually get regular hand backs from HMRC, not paying tax releases funds to me that otherwise I would be paying.
It depends on your personal expectations, expenses, and the amount of debt you have.everyone is different.
It sounds like you might have a case of constructive dismissal, but dignity g that waiver queers that pitch.
Speak to your pension provider and ask what options are, for me I took a lump sum, and a reduced occupational pension , with an added subsidy, which runs out at my state pension age , hopefully that goalpost won't be moved again, and then I have a substantial increase.
I can pay my bills , but I have to be frugal.