@RokoRebic Hello,

have you tried do to a factory reset of your phone - where it’s set up as a new phone without any data on it? If not, please try that before creating sending it in for repair. Remember to back up all of your important data in your phone. 
 

If you have the possibility, you can also contact Samsung Care and see if they can help you. 
 

If this does not help - I’d recommend you to see if Samsung can help with the warranty. If not, it’s best to contact the reseller. In this case Media Markt.