I have been Comerica bank for almost 10 years. There have been a few instances where I have faced rude people or had real issues:
1) When trying to activate my debit card over the phone. After 15 minutes of dealing with the rude lady and her attitude, she could not "help" me. I had to go to a branch to activate my debit card. Very annoying.
2) When I was told that I could not add my husband to my account in a different branch from where I originally opened my account.