Crossover on credit reference - help!

[ExpatMrs]

My SIL and I have very similar names since she married my DB. Eg say our surname is both now Smith but my first name is Julie and hers is Julia.
Anyway, she's signed up for Equifax and they email her if any anomalies appear on her credit reference report.
Now, to give you enough info, quite a few years ago I was up financial shit creek but have now sorted myself out and I have lived overseas for several years since.
Anyway, apparently an outstanding dispute is still registered against me for a mobile phone company (this actually wasn't one of my debts, there was massive errors on their part but that's irrelevant). The problem with this dispute is that it has become attached to my SIL's credit file and she's going crazy (understandably).
She's contacted the mobile phone company and explained that we are diff people and she's provided proof of her DOB & slightly diff name but they're refusing to budge. It's clearly a mistake on their part as she's never even been a customer.
How can she get it removed? They're classing the slightly diff name as an 'alias'

Anyone?

The first thing your SIL has to write to the company and formally make a complaint, requested the look into the debt, make it clear she has no connection to the debt she can threaten them with the financial ombudsman if they refuse to sort it out.
She then needs to write to the credit reference agencies and tell them the debt isn't hers, they will do an investigation and when they find that the debt belongs to Julie smith with the DOB XX/XX/XXXX and she is Julia smith, DOB YY/YY/YYYY
they will remove the incorrect information from the credit file and give her an updated copy.

She has to do it with both the major agencies (Experian and exquifax) to ensure it is done completely.

The company may be being difficult because she told them you are her SIL so they may think she will be able to get you to pay off the debt to get it off her file.
She should stop explaining who you are, as far as they are concerned all they need to know is the debt is not hers.

I told her not even to mention our connection for that reason but I'm not sure what she's told them. I'll pass on your advice and appreciate you taking the time to reply WeAreEternal