How to say: I got someone wrong with someone else? Like I want to talk to Ben and I call you (while thinking you are Ben) And when I see you are not Ben, I say: Sorry, I got you wrong with Ben.
Generally, the three most common ways to say that would be these:
I'm sorry. I mistook you for Ben.
I'm sorry. I thought that you were Ben.
I'm sorry. I confused you with Ben.
In the second example, you can also drop the conjunction that altogether and just say:
I'm sorry. I thought you were Ben.