A member may be expelled by the vote of a majority of the members voting at a regular or special meeting. The member against whom the charges are to be preferred shall be informed thereof in writing at least 10 days in advance of the meeting, and shall have an opportunity to be heard in person or by counsel at said meeting. On decision of the association to expel a member, the board of directors shall purchase the member’s holdings at par value, if and when there are sufficient surplus funds.