I had my roof replaced (shingled) by a company that made me…

The easiest course of action is likely to contact the two credit rating agencies, Equifax and Transunion Canada, and dispute this charge on your credit, arguing that there has been no judgment indicating that this amount is owing by you.

If they will not change your credit rating based on what they've been told by the creditor, then you can threaten to sue or suit accreditor for defamation, arguing that they are making false statements about you that are damaging your reputation, claiming that you owe money that you do not in fact owe. If you actually proceeded to Sue, the court can make a declaration that the reporting to the credit agency is false, and they still not to the credit-rating he should be altered.

It is legal to threaten a civil lawsuit, see you can tell the collection agency and if they do not revise their report to the credit agencies, that you will be suing them, seeking a declaration, and court costs payable by them to you.

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