It doesn't always happen like that, so I wouldn't be too hard on yourself. I had an account closed like 10 years ago. I later learned all my business transactions had gotten me flagged. They wanted me to get a separate business account with them, but instead of just telling me that, they shut down my personal account and locked access to my funds.

Anyway, I had another account linked back then so I could transfer funds as needed. They didn't send my balance to that. They sent a check in the mail (supposedly), which I never received, so I finally got my lawyer involved and drove to the closest branch even though the bank originally told me I couldn't do that. They magically were able to cancel the check that was allegedly sent and write me a new check right there at the branch. It was a huge hassle and I'm not sure it would have gotten resolved without my lawyer's help.