A key office in the Department of Education responsible for fielding grievances about student loans has a backlog of more than 27,000 complaints after losing nearly two-thirds of its staff.

The department revealed the pileup in a July 21 letter to Sen. Elizabeth Warren, D-Mass., according to a copy provided to NBC News. The Federal Student Aid ombudsman office receives hundreds of complaints a week, related to problems with student loan processing, repayments and financial aid scams.

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The office closed just over 1,100 complaints in May, the most recent month with available data, and Warren wrote in a letter to Education Secretary Linda McMahon on Wednesday that this pace made her concerned that the backlog will c

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