Discovery Insure - managed to get premium reduced.

I got my insurance renewal notice and nearly died at the huge increase in premiums quoted. I phoned, but their systems were down. The promised return call never came, so I called again. I got put through to Kastello Govender in the Discovery Insure Retentions Department. He listened politely to me; heard what I was prepared to pay (based on another written quote I'd got from another company) - and matched it. Thanks Kastello!!! Much appreciated so four stars (you deserve five but Discovery Insure's prior actions prevent that). Question: - why did I have to threaten to leave Discovery Insure before being offered a more reasonable premium? Why is it necessary for insurance companies (Discovery is not the only one) to have a retentions department to deal with unhappy clients and resolve their issues?