Got scammed by the Porsche Dealer during service with aftermarket parts and used brakes/rotors?

Just got back my 2018 Macan GTS from the local autobody shop. Went in inspection and replacement of back brake pads and rotors. Ended up having to replace all 4 brakes and rotors. I was surprised that all 4 were needed as I said I had the front replaced only a year ago. Mechanic told me that the only way for me to have this much wear on the front pads / rotors was for me to have driven all 10,000 miles with my foot on the brake the entire time. In addition, he told me that there were aftermarket parts put on the front.

The thing is.... I brought this car to an official Porsche dealer in February 2024 and had a 40,000 mile service and replaced the front brakes and rotors - only have an additional 10,000 miles on the vehicle since then.

I think the Porsche Dealer charged me for service never completed, or put used / aftermarket parts on my vehicle and charged me for original parts.

Am I just screwed here or is there any recourse with Porsche directly? Anyone deal with something like this before?

Before anyone asks, local autobody shop is a stand up garage that many people I know use and trust.