Unable to blacklist a device due to failed security questions

<p>I have been phoning cell c for the past 3 weeks now to blacklist 2 devices and they keep on asking security questions of which "some" of the questions are failed and they cannot tell you which ones they are. A 9 year old is supposed to now remember recharging from more than a month ago....I went in store and was told they can see the device but cannot blacklist it I need to call in. Pathetic really!!!! </p>