Mechanic misdiagnosed car?

To start off, I have a 2007 Ford Focus. Approximately 2 weeks ago I took the car into my mechanic because the steering wheel was making loud noises when I made turns. The mechanic charged me a diagnostic fee of $60 (which went toward the cost of fixing the car).

After diagnosing it, he said that the power steering pump needed to be replaced. He quoted me $380, and I paid. About a week later, the issue occurred again. I took the car back in, and he replaced the power steering pump again. The mechanic told me that pump they put in wasn't working, and was covered under warranty.

I wasn't too upset until I was told that if the pump has the same issue again, it's going to be approximately $700-$1000 to fix the vehicle. I can't remember exactly what the issue was, but I'm confused because shouldn't that have been revealed when the diagnosis was done?

I feel like they're giving me the run around

Oil change for 2013 ford focus st?

My mechanique did a oil change, on my 2013 focus st. He used full synthetic oil 5-30w penzoil, I belive thats the brand he used not sure. He used 7 litters of full synthetic oil 5-30w, I was shocked for a 2.0 liter turbo? I thought full was 5.4 litters on manuel book but I noticed the manuel book is just for a regular focus. I also noticed focus st is a pretty big engine for a 2.0 litter turbo. Anyways is this the full capacity for oil change on focus st?