It's true you can't please everyone.
I had a client the other day email me a fairly passive aggressive email. In short, she was wondering if I had time for her. She wanted me to show her that I had done something that she had asked. Well, interestingly enough her peer told me not to, and this client was copied on the email. Instead of apologizing, this client basically made an excuse for not seeing her own peer's communication.
Even though I was on top of the project, the client jumped to conclusions. She rang the bell as it were. It's frustrating because you know you are doing everything right, but the client - at least momentarily - has a different perception, or expectations.
I was pretty ticked off. I wanted to fire this client. I suggested to my team that I would. I learned two lessons from this transaction. One, it's not all about me. It's about the team. Sometimes, you have to take one for the team for the betterment of the group. The client is paying the bills so to speak.
Two, unmet expectations seem to be a byproduct of lack of understanding or miscommunication. Sometimes, the complainer just does understand what is going on even though it was communicated to him or her. They are not taking the time out to review the communication. Instead, they top-sheet and jump to conclusions. The net result is usually engaging in the blame game.
I was able to respond to this client with poise but with directness. In the end, sometimes it could be that the relationship has gone sour. In business, it could be what Dr. Henry Cloud call's "Necessary Endings." If the relationship is not good for me, and not for you, perhaps it's best to cut the losses and move on. There's no shame in that.