You would have no reason to sue them; whether or not you actually have to pay to fix their mistake would be a matter of the contract between you and your state's law. Regardless, they'd likely just adjust your financial aid in the future and you still have to pay back the loan anyway.
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I do not see this as a matter for the courts. Along with the immunities from suit the school likely enjoys, the observations of Mr. Swanson are accurate.
Good luck to you.
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