Prior to instituting proceedings for withdrawal of a certificate under paragraph (a) of § 528.3, except in cases of willfullness, an area director shall mail a letter to the employer setting forth alleged facts or conduct which may warrant withdrawal of the certificate, and fixing a time and a place for a conference at which the employer shall be accorded an opportunity to show that no cause for withdrawal under § 528.3(a) exists or that compliance has been achieved by paying wages improperly withheld and by taking steps adequate to insure that new cause for annulment or withdrawal will not occur. By written report to the appropriate authorized representative, a copy of which shall be mailed to the employer, the area director shall concisely summarize the conference and shall include conclusions as to whether the employer demonstrated or achieved compliance. If the authorized representative is satisfied that the employer either demonstrated or achieved such compliance, no proceedings shall be instituted under § 528.3(a) for the withdrawal of the certificate.