Hyundai 5 Year Warranty a Gimmick!

I once was a proud Hyundai owner, boasting about the 5 year warranty. Now I'm not so sure. I have a Hyundai IX35 with 42 000Km's on the clock. This vehicle has only ever been serviced by Hyundai Sandton, and when I went over a boulder the radiator and exhaust was repaired by Danmar Sandton, and approved Hyundai repair centre. My engine started over heating and I took it into Hyundai Toti. I'm told that it has a radiator blockage and the engine needs to be stripped and an ultrasonic clean done at my expense. Why should I pay for a repair on a vehicle that has only been touched by Hyundai approved people. I have not even opened the bonnet on that car. Well, I'll wait to hear how Hyundai handle this, but I will also make sure that everyone I know does not buy a Hyundai. I knew that warranty was too good to be true...false advertising maybe??