Sales scam on Facebook Marketplace with threats over package

Hello, I bought a PC on Facebook Marketplace. The thing is, the seller is from another city and sent me the package blindly. He wants me to pay about 150 USD. The issue is that I don't know if the box contains the complete PC or just a very expensive case, or even worse, a brick wrapped in clothes. So the guy decided to threaten me. I received calls from 3 unknown numbers to pressure me. Thanks to AI, I was able to get out in time, and I also found this wonderful app.