Effect of Outstanding Balance of Zero. If the outstanding balance of an enrolled loan that is not a line of credit is reduced to $0, the loan is no longer an enrolled loan. If an enrolled loan that is a line of credit has an outstanding balance of $0 for a period of 12 months, the line of credit is no longer an enrolled loan, unless, before the expiration of the 12-month period, the lender reaffirms in writing to the borrower that the line of credit will remain open and the borrower acknowledges the reaffirmation in writing. Notwithstanding §A of this regulation, any amount recovered from a lender by a trustee in bankruptcy, or a similar representative of creditors, as a preference under 11 U.S.C. §547, remains an enrolled loan for the purpose of filing a claim against the reserve account.