This is an interesting question. My first instinct would be to say that the bank has the right to protect its interests, and as it believes its interest is impaired by the existence of your joint account, then it had a right to close the account.
But, the question of whether the bank has the right to damage your credit report, is a question that I don't believe has ever been adequately addressed under Ohio law.
Because under ORC 3103.08, neither spouse is answerable for the acts of the other. The bank may have violated your rights, if it reported your joint account as delinquent in some manner. But, it's not a negative report if all that was reported was that your joint account was closed -- so, it depends on exactly what was reported.
Re trying to reach you to pay your spouse's debt, the bank can reach any joint account or asset, because it is a principle of joint holdings that all joint holders are jointly liable to the extent of their holdings. And, so a creditor can reach the joint property to satisfy its debt -- which may seem to you like taking your property. But, if it's in a joint account, then it's both yours and your spouse's property -- legally speaking.
The bank cannot reach any account that is in your name only -- unless you transferred demonstrably joint assets with the intent to avoid the bank's collection efforts.
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