Cable and telecom companies love to sell you on the convenience and affordability of bundles combining phone, TV and Internet service onto one bill. But what they don’t tell you is that shedding that bundle could end up in a billing nightmare.

Over at Credit.com, columnist Bob Sullivan writes about one AT&T customer who previously had a phone/TV/Internet bundle through AT&T U-Verse. Then in 2011, she dropped the phone and pay-TV services and went with only U-Verse broadband.

Shortly after dropping the bundle, AT&T alerted the customer to the fact that there was a balance of around $70 remaining on the bundled service. She sent in payment for that amount, which appears to be the last thing upon which she and the telecom titan agree.

AT&T says that it — inexplicably and without telling the customer — applied that payment to her new account that was in good standing, rather than the account for which it was intended.

And yet it sent three different collections agencies after the customer. Each time an agency contacted her, she’d write them back to show them proof of the $70 payment from 2011 and she’d never hear from the same collector again.

But they continued to come after her. When Sullivan got involved, the reason why this bogus debt refused to die became slightly more clear.

Apparently, AT&T had not sold the debt to the agencies, but merely assigned it to these third parties. At some point, AT&T recalled that debt — again, without explanation — so the collectors just stopped trying to pursue it.

See, the Fair Debt Collection Practices Act requires that collectors provide proof of a debt when challenged by an alleged debtor — but only if the collector intends to continue pursuing the debt.

If the company believes the consumer — or has the debt recalled by the company that assigned it — there’s no requirement to respond.

And even though AT&T recalled the debt from the most recent collections agency, it still maintains that the customer owes the $70… because it apparently screwed up and applied it to the wrong account.

After Sullivan got involved the Death Star is suddenly willing to work with the customer. Luckily, since the collections agencies were working on behalf of AT&T the disputed debt had not been reported to the three major credit reporting agencies, which would have stained her credit report.

But let her story be a lesson to anyone who is changing plans within the same company. Check to see if you’ve been given a new account number, and to make sure that all accounts are settled. Just because you send in a payment doesn’t mean it’s going to the right account.

UPDATE: A rep for AT&T has provided the following statement to Consumerist —

“This customer has had an outstanding balance on her former account since 2011 that was never paid, ultimately resulting in the bill being sent to collections. Once we were notified that the customer claimed to be wrongly charged, we conducted a thorough account review and determined the outstanding balance was indeed still owed.”

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