No bond required under this article shall be released until the contract for which the bond is given has been fully performed and until the commissioner obtains a written release from the Commissioner of Labor certifying that all contributions and interest due from the principal on the bond under Chapter 8 of Title 34 have been paid in full. Bonds shall be released automatically two years after written notification of the completion of the contract is received by the commissioner unless a court proceeding has been instituted against the contractor.