impossible security questions

CellC insist on asking security questions that are difficult to answer so much so that it is impossible to get a service from their call centre. I have a tablet that I use for data only but if ever I need assistance especially when my data bundles do not work, the call centre insists that I must remember the last three calls made, the last date of recharge etc. This is **************** and incompetence. they should be flexible to ask other security questions.Security questions should be for helping the consumer not blocking them to get the services they pay for.There sure are other questions that can be securely used to verify.