Sprint tech here. The techs you're talking to are idiots. Our M&P officially states that we support rooted phones. Worst case scenario, they will have to RUU the phone for you. After they've done that, the issue will still be present and they'll have to order a new one for you. Go back and insist that they do their job. If you need me to, I can try to pull our M&P document tomorrow and send it to you so you can show them.
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