Unless otherwise provided under the express terms of the agreement governing a revolving credit plan, the provisions of Subtitle 1, 3, 4, 5, 6, or 10 of this title do not apply to any extension of credit made pursuant to a revolving credit plan if: The plan is established before October 1, 1993; and The extension of credit is made under this subtitle before October 1, 1993. For the purposes of subsection (a) of this section, an extension of credit is made under this subtitle if: The credit grantor has made a written election to do so in the agreement governing the plan; or The agreement governing the plan is offered pursuant to the provisions of this subtitle. For the purposes of subsection (a) of this section, if there is no written election to extend credit under this subtitle in the agreement governing the plan, the burden of proof is on the credit grantor to show the agreement governing the plan was offered pursuant to this subtitle. Any plan established before October 1, 1993 is not subject to § 12-913.2 of this subtitle.