(a) An attorney subject to the disciplinary jurisdiction of this Court shall be deemed to have agreed to arbitrate disputes over fees for legal services and disbursements related thereto when such arbitration is requested by a present or former client, if such client was a resident of the District of Columbia when the services of the attorney were engaged, or if a substantial portion of the services were performed by the attorney in the District of Columbia, or if the services included representation before a District of Columbia court or a District of Columbia government agency.
   (b) The arbitration provided under this rule shall be final and binding on the parties according to applicable law, and shall be enforceable in the Superior Court and in any other court having jurisdiction. Unless the attorney and client agree otherwise, the arbitration shall be before the Attorney-Client Arbitration Board of the District of Columbia Bar, and shall be pursuant to such reasonable rules and regulations (including those relating to fees for arbitration services) as may be promulgated from time to time by the District of Columbia Bar and the Attorney-Client Arbitration Board.