What you describe is not the crime of passing a bad check. Passing a bad check is only a crime if there can be shown to have been an intention to write or pass a bad check. An honest error--writing to the wrong person; accidently writing a check from small or closed account 1 instead of ample account 2 as had been intened; etc.--is not a crime so long as the evidence supports that it was an honest error. You have been paying on the check: this shows that there was no criminal intent. They could sue you for any unpaid money, if they grow impatient with your repayment schedule or you stop paying, but you should not face criminal liability in the situation you describe. Even if they lie to the police to try to get you arrested, when the true facts come out, you should have a good defense.