Hyundai alberton shocking afters ales service

Bought a brand new top of the range tuscon N series. With the last service the car had to go back 3 times because of brakes shuttering. The radio GPS was giving problems and just before the 60000km mark we ask Alberton hyundai to check it out. We complained before about the GPS losing signal but still working fine Eventually after first saying the the warranty of the radio has expired we had to proof to Alberton with enatis papers, (which we bought from Alberton) that the warranty had not extended the 3 year for radio warranty. Long story short they took out the radio send for repair put it back and geus what now it doesn't even go into GPS function at all. The service manager Steven and blatantly refuse to help use and according to him he also is backed by his DP he says it is our responsibility to replace the '*******ed' SD card after they 'fixed' it. After sales service for a 500k +car is shocking to say the least. This will be my last hyundai... I'd rather change vehicle brand. We also send a email to hyundai sa a complaint email... NO RESPONSE FROM THEM EITHER