Bad service

so disappointed - I bought a Mercedes 2nd hand from the dealership . On the 12 October 9 (the day after I bought the car) I phoned the sales guy Deon and told him that the visor was broken. he said not a problem they will get me a new one. to keep a long story short - it's now 5 dec and I had to drive down to KZN for my dec holiday with no visor and the one I had they actually broke even more to such an extend that it cannot be used. meaning it's now dangerous to drive around in this car as the sun cannot be blocked out!!! Shocked in this poor service from the dealership and the sales guy Deon!!