Bank account levies

I own an s- corporation. There was a levy put on my business account. It is not the IRS or the State. Although I owe some taxes I've spoken to both and they say it wasn't them. My bank is unable to tell me who the judgement is from or if there even is a judgement. They say they don't know. My question is doesn't the bank have to tell me who has frozen my funds? And how could someone levy my account for something personal when its an s corp? And what should my next step be if they won't tell me who is responsible? Thank you, jason