Sorry for the long question, it is necessary.
My car is a 2015 Kia Forte Ex (GDI engine 20k miles)
I took my car to get an oil change, tuneup etc. They messed up and it had a major oil leak which became apparent after 5-10 minutes. Had new tires so I was testing them (hard accelerations). Everything seemed fine but I noticed a slight rattle. I know thats not uncommon with GDI engines after an oil change but it sounded different. I ignored it thinking im paranoid.
Then it had a loss of power which I ignored for a short time until on the interstate when I floored it and it didn't even rev past 2k rpms. It felt like more of a transmission issue at that point. Temps were normal, no lights but I thought I smelled something so I pulled over. I come to a stop and THEN the oil light comes on right before turning off the engine. There was oil dripping out (not transmission fluid).
My question is:
I'm going to the repair place where it was towed back to, tomorrow and since I don't trust them obviously, I don't know if I should demand an engine replacement or does it just need oil and the leak fixed? The engine didn't "seize" as in stop running but idk if the loss of power was physical or the computer as there were no warning lights until I stopped. How do I know this is not going to cause engine failure in 5k miles?