In life and business there will be disagreements... and where we find humans there are emotions.
This can be a dangerous combination.
While trying to resolve an issue, beware of getting nasty in your conversations. People often have a knee-jerk reaction and jump to the conclusion that the other party is intentionally screwing them over, but often that is not the case. Since there are two sides to every story, on occasion you may discover that you are the one who is wrong or that it is simply a misunderstanding. Once you have been nasty it is difficult to put that genie back in the bottle.
It gets worse if you have been broadcasting your problems to others, as word of your rant will get back to the people you are bad-mouthing. In the end, you look small and it is tough to recover because your own ego gets in the way and fessing up to what went down and repairing the damage is often impossible (I know, as I have been there and made these mistakes!).
Not every conflict has to be adversary. Most people are not actually out to get you, and thus most disagreements eventually work themselves out in the end. Burned bridges are opportunity lost for everyone involved.
Have A Great Day.