In a word, no.
Sorry, but principal payments for such loans are not deductible.
And you can't deduct the interest on a student loan unless you receive a 1098-E form in the mail. Note that this is independent of how the loan is repaid.
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Once you defaulted on the loan, it instantly lost it's "qualified" student loan status. Therefore, if you didn't get a 1098-E, the loan is no longer a qualified loan and nothing concerning the loan is deductible on any tax return.