Aamco of Lawrenceville,Ga Tried to sell me a new transmission when the one I had was in perfect condition! Lawrenceville,Ga.30045 N.C.

I brought my 2014 Nissan Altima to this Aamco Transmission Specelist to see why it was acting erratically. After inspection they said the transmission was unrepairable and had to be replaced and not repaired because it is a CVT type transmission and that it couldn't be rebuilt. The esitmate was $3000 to $4000. I decided to get a second opiniion at another Aamco shop and it was the exactt same story. I then decided to haul it North to "My" mechanic and found that the exhoust pipe and catalitic converter had been crushed, which was putting the car in limp mode. I replaced the exaust pipes for $160.00 and the car has run perfectly ever since. What do you think ? Is Aamco a ripoff?