Other people are going to behave badly at times. Or, at least, they are going to behave as they wish.
A distinction must be drawn between the emotional level and the practical level.
If I am disturbed by someone else's behaviour, they have not followed my script. My script is the cause of the disturbance; no script: no disturbance. Acceptance is therefore mandatory if I am to be at peace. Not accepting something, at this level, is entirely self-defeating, and achieves nothing.
To accept does not mean to say that something is 'OK'; to not accept does not mean to say that something is not 'OK'. Sometimes people say they cannot accept something, because to do so would be to say it is 'OK' or to condone it.
This makes about as much as sense as not accepting that bees sting, because to do so would be to condone the bees for stinging. Bees sting. Full stop. There is no point in complaining that bees sting, or that the sky is blue or grey, or that the sea is wet and salty. I may not like such things, because they do not fit my plan, but the universe is not terribly interested in the plan. I am the one who came up with the plan, all by myself.
So, to sum up, on an emotional level, I can choose between acceptance or maintaining the fiction that the universe presented is somehow 'wrong', and that my alternate universe is the real, genuine, valid one.
This does not mean that the future universe cannot be different and better. It means merely that the current universe is as it is.
One can be accepting at the emotional level, e.g. that there is injustice, poverty, violence, etc., in the world, but work actively towards its elimination. The active combatting of wrong does not require me to be or remain angry, and acceptance actually makes it easier to work for a better future for all.
From a practical point of view, acceptance is vital, also.
What this means is the recognition that most people and situations are largely non-negotiable. They are as they are. I can accept them in my life, lock, stock, and barrel, or jog on, and find a person or situation that is more to my liking.
Within the very limited bounds of negotiability, there are five ways I can effect change:
(1) Polite request: this is the ideal.
(2) Transaction ('If I do ..., you do ...'): this represents a 'fair' exchange, and often works well, too.
(3) Overt control/boundaries ('If you ..., then I will ...'): this is where we state the consequences of someone else's actions, in terms of how we will respond, e.g. 'Let's meet at 8.15. I will wait for fifteen minutes. If you do not show up, I will go at 8.30,' or 'if you carry on shouting, I am going to put the phone down,' or 'If you do not hand in your work on time, I will not mark it.' Sound judgement is required to discern whether we are acting within the bounds of fairness. This remedy is to be used sparingly and with a light touch. Clearly, there are inappropriate varieties, e.g. unreasonable threats, especially of punishment or withholding of love.
(4) Covert control/boundaries (e.g. not responding to aggressive emails). This is the same as (3), but with the consequence unstated and implied.
(5) Force (changing the locks, calling the police, etc.)
There is scope for all five, depending on the circumstances, but, in order not to be excessively disagreeable, I need to use all but the first two very sparingly.
In short, other people's bad behaviour is generally to be accepted as one accepts the weather or illness. Railing against it will not help, but evasive measures and remedies are available.