Can a car fix last seven weeks?

Bought a used Porsche Cayenne S at the Jim Ellis Audi Marietta dealership.
The next morning the middle console (navigation, GPS, radio) shut down.
I asked them if they sold me a lemon and they assured it's not the case, the sales associate offered to drive to my place the next day with a loaner car which I will drive until they fix the problem. This was on a Friday and I didn't want the guy spending his Saturday with this, since my place is about two hours drive from the dealership. I said I will drive there on Monday, so I took a vacation day and did just that. I got the loaner car and left the Cayenne.
It was seven (7) weeks ago.
I inquired a number of times and they were always nice when talked to me but more often than not they didn't respond to my emails, texts etc.
I got some updates that the part is expensive and they have to order it and all.
I'm sympathetic to them in general but seven weeks looks an awful lot of time to fix an issue and the problem comes down to the fact that the person who did the checkups on the car before selling it, didn't do a great job at all...
Buying a used car there most likely not a great idea either.