Mutual and Federal insurance Bond B19874/1996

We own a house with Mutual and Federal as the Bondholder. Mary Hoover worked for Mutual and Federal at the time. The bond B19874/ 1996 is registered in the Deeds office in Pietermaritzburg and is in the name of Mutual and Federal insurance. Old Mutual has taken over Mutual and Federal , and we are led to believe that OMINSURE is the Old Mutual division that would have take over Mutual and federal. However all calls to OMinsure and old Mutual are leaving us with no information, with respect to cancelling the Bond. We have a buyer, and they will sue us for holding up the sale. OMinsure are not denying any knowledge of the Bond.