If you contend that AT&T and a debt collector have furnished incorrect information to a credit reporting agency, then you can sue AT&T, the debt collector (and the credit reporting agency -- but, only if you first dispute the negative report and the credit reporting agency refuses to delete the incorrect report) under the federal Fair Credit Reporting Act (FCRA). Federla law permits the court to award you up to $1,000 in damages from each of the defendants, for a willful negative report.
This type of case can generally be brought in small claims court, without a lawyer. Or, you can hire a lawyer to sue, and assuming that you win, the lawyer would be entitled to attorney's fees paid by the defendant(s).
Letter writing from a nonlawyer will generally be unproductive (except to the credit reporting agency). Large organizations and debt collectors typically ignore consumer complaints. Frankly, they typically ignore me, even though I'm a lawyer. The only thing that gets attention is an actual lawsuit.
If you need a link to a reputable lawyer referral service, please let me know and Ill be happy to provide further info.
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