Saru you have a good reason for leaving in that you want to, nothing at all wrong with that and can I wish you luck in your next job. It is sad that you have been effectively bullied out of a job you like and that to me is unacceptable, but is a symptom of the way Royal Mail is being run from the top. However, your well being and happiness is more important than anything and for that I commend you for making a brave decision to leave a job you like.
My sentiment is directed at those members of the public, and a few on here, who say if you think things are wrong you should leave and accept it, but I myself feel that for me I would rather try and change things from the inside rather than the outside. If we all accepted the argument of leave if you don't like it then women's Suffrage would not have as successful as it was,. Children would still be working in mills and mines, because, after all if the Unions and workers who had not accepted this state of affairs had just left, instead of acting against that injustice, nothing would have changed for the better.
I am in no way comparing our current position to children working, we are well beyond that stage, however the sentiment remains the same, if you don't like a situation either leave if you wish or stay and fight to accept it. Your decision Saru is good for you personally and though you are leaving, you are not accepting the situation, merely leaving and trying to make your situation better.
What, in my stumbling way, I am trying to say is that your reason to leave is just as good as mine to stay, perhaps even better. But just to accept a situation people see as wrong and decide to do nothing about it but turn your back on it, that to me is indefensible. Basically my stance is if a certain action benefits you and your immediate family then that is the choice you should take, be that to stay and fight, or to leave and make the situation better both are positive steps. But to leave and ignore it just because someone else thinks that's the right thing to do, sorry that's not in my make up.
I hope you see what I am trying to say. Make a positive decision (which you did) rather than a negative decision (which is what some mean when they say if you don't like it leave).
for the if you don't like the leave brigade.