About 16,600 insurance contracts with the failed Nissan Mutual Insurance Co. had been canceled as of Oct. 14, according to Aoba Life Insurance Co., which took over Nissan Mutual's operations.Aoba began operations on Oct. 1, and the rush to cancel policies hit immediately, apparently out of apprehension among policyholders over the new firm or out of distrust of the life insurance system. Cancellation and insurance payments had been frozen since April 25 after the ailing Nissan Mutual was ordered by the Finance Ministry to shut down, the first closure in the post-World War II era.Meanwhile, Aoba has recovered about 80 percent of the insurance payments and surrender values it mistakenly disbursed on its first day of operation, according to the firm. Because of clerical errors, a total of 13 billion yen in miscalculated payments was paid out.The number of cancellations so far accounts for 0.9 percent of total policies. Some 16,000 policyholders have visited Aoba's head office and seven branches across the country and another 17,000 have called regarding cancellation, the firm said.