What's the meaning of "one too many times"? [closed]
Solution 1:
It means they have crossed some threshold that caused the speaker to take action.
In this case, it sounds like "WF" did things such as charging for previously free services and the speaker felt that this last activity "charging me for things I had for free for 6 years" was too much for them ("burned one too many times") and prompted them to go and get an account with a local bank (who presumably does not charge for the same services).