Everything went well with regards to purchasing my...

Everything went well with regards to purchasing my car however, when I emailed my sales associate to tell him about an issue with the car I heard nothing back. I don't have time to go to the Sterling location and was thinking the sales associate would have emailed me back or called me to handle the issue however, he never did.
The seven day window to bring the car back has passed which is what I think he was trying to avoid given the amount I paid for the car.
The car I purchased had an aftermarket exhaust installed in place of the Chevrolet NPP exhaust which allows you to change the tone and quiet your exhaust from extremely loud to stealth mode (aka good neighbor mode).
When I went to go to work the next morning (445 am) I attempted to put the car in stealth mode but nothing happened with the tone. After work I took a look and discovered what is considered one of the loudest axle back exhausts in the market today, a Corse Extreme muffler installed on my Camaro. I didn't realize the car had a different exhaust because I figured the stock NPP exhaust was set to sport/track mode in the settings resulting in a very deep tone. Upon the first start in the morning my car wakes the entire neighborhood! This isn t necessarily a show stopper but I would have liked the sales associate to reach out to me and discuss the matter further and come to some sort of resolution if we could.
My HoA has quiet hours and therefore I cannot use the car to go to work. I have already received several complaints that the exhaust is too loud. What was a great sale has since manifested into an ugly question stating why did I buy this car? This is the second time a CarMax associate has not reached out to me after I have purchased a car.