Sallie Mae, one of the U.S. Education Department's (ED) preferred student loan providers, was the subject of harsh criticism from a certain federal consumer regulator.

In a recent blog post, the Consumer Financial Protection Bureau's (CFPB) top official on student loans, Rohit Chopra, highlighted Sallie Mae's poor customer service figures and increasing government scrutiny, the Huffington Post reported.

The post relied on ED surveys from its four preferred student loan providers: Sallie Mae (SLM Corp.), Nelnet, Great Lakes Higher Education Corporation and Affiliates and the Pennsylvania Higher Education Assistance Agency (FedLoan). Chopra used the surveys to determine how many loans each will receive with a new batch of incoming freshmen and outgoing graduates.

Chopra said Sallie Mae would receive the least amount of new student loans in the upcoming academic year.

"Sallie Mae ranks the worst in borrower, school, and federal personnel satisfaction," Chopra said.

The public criticism comes in the midst of multiple probes into Sallie Mae's practices. The U.S. Department of Justice (DOJ) and federal banking regulators are investigating SLM Corp.'s handling of student loans and how they treated their borrowers. Another CFPB previously warned to Congress that borrowers trapped in long-terms repayment plans with servicers are more likely to experience poor service and consumer harm.

Much to Sallie Mae and its investors' knowledge, the Federal Deposit Insurance Corp. (FDIC) is expected to publically accuse the student loan lender of violating federal laws. The ED is also probing this issue.

Sallie Mae is the government's largest contractor for student loans, but Sen. Elizabeth Warren wrote a letter to Education Secretary Arne Duncan why his agency has not hit Sallie Mae with any sanctions, like fines or loss of contracts.

Warren said in her letter the ED has the capabilities to reprimand Sallie Mae, but has issued "little more than a slap on the wrist."