Here's my measuring stick. While the principle is important (who wants any amount of money unjustly taken from them?), for me, it can't just be about the principle. If I'm going to spend my time calling customer service, I have to be getting something out of it other than the satisfaction that I've put the company in its place. With the ATM fee, the problem was a broken machine. I'd inserted my card, stared at a blank screen, and then removed the card without conducting a transaction. But their system charged me anyway. This probably didn't usually happen, and I don't think the company was trying to pull one over on me. Personally, it wasn't worth my time to spend upwards of 20 minutes on the phone; I would just avoid using ATMs in the future, being especially aware of the “glitches” of this particular company.Chase, on the other hand, was a different story. I genuinely believe they needed to be put in their place, and while I broke up with them for my own sanity, I did relish the fact that I was justly serving “the principle.” I could have left the account open and just never used it, but it was worth my time to never worry about any issues with them again and let them know why they had driven me to that point. After spending months arguing with them over some fraud charges, I figured I was already invested in this argument, so I was past the point of no return. It was worth it to go a bit further and end things altogether. Putting up a fight…or not It's bad enough when dealing with customer service problems that you have to spend your free (or sometimes work) time correcting someone else's error. But, man, these institutions can really drain the life out of you. It's easy to get mad when some company is charging you an unfounded $100 “processing fee” (sadly, a true story), but the last thing you want to get is emotional. As the saying goes, you attract more flies with honey, and you want to spend as little time arguing your point with customer service as possible. If you find yourself getting heated, annoyed, or you begin to raise your voice, I've found that the best thing to do is to hang up and deal with it later. Being relentless is one thing, and it's sometimes necessary when you need to talk to a supervisor, but you've already lost your money and time - don't lose your cool while you're at it. Avoid it in the first place Going back to the Chase example, I could have avoided that headache altogether. I joined Chase because a friend of mine used them and told me she had racked up enough points to earn a free flight. “Wowee! A free flight,” I thought. I was young, OK? I didn't know better. And a lot of my friends had Chase, so I figured, Chase must be great. I didn't read any reviews, didn't consider my longstanding relationship with my current bank - I switched banks that week, dreaming about my flight to, oh, I don't know, the Bahamas or something. You know how the story ends, and no, there was no free flight. The point is, I could have avoided that entire headache by doing some research and not being impulsive.