2017 AUDI A8 Forward Collision Avoidance Adaptive Cruise Control Problems

Bought a 2017 audi A8l with 51700 miles, from Mike erdman Nissan in coco beach florida, it had front grill damage and when you try to use the cruise control message comes on dash ACC and brake guard disabled, i told dealership they first said theyd fix it but i had to talk to the lender first then theyd fix i talked to the lender now they are refusing to fix it, i never signed anything saying no warranty, nothing was never said about warranty, but was told but eric the salesman that he was going yo have it fixed