my radio is not working and navigation. everything is frozen and will not work
Do they have power? If they do, look for ‘reset’ instructions in your owners manual.
Mercedes offers a 48 mo./50k bumper-to-bumper warranty on new vehicles and 12 mo./unlimited mileage on certified preowned so you might have some recourse depending on when and under what circumstances you bought it. If not, I’d try a car audio shop.