Insurance that robs people

I've made a cellphone claim through jet in Palm Springs, in September for a cracked screen. In August I received my cellphone back after it had a cracked screen it was repaired and I was happy. My phone came with a warranty that if it were to come back again it wouldn't be a second claim if its before the three months warranty. I took my phone back to jet which stayed there for over a month without anything being done to it, after my consistent enquiries they finally came back to me and said I should pay an excess of R400 before they fix my phone. I told them I have a warranty letter from them and they said a warranty doesn't mean anything they just can't fix my phone for free rather I pay R200. I mean why do we still pay insurance if they gonna rob us of our money in the day light. This kind of service is uncalled for and I would recommend them to anyone.