2002 Ford Focus new lifter

I bought a used car 2 1/2 mos ago. This past week while driving up a mountain the car downshifted to maintain speed. When it downshifted my car felt as if it had no power, like I was running on 2 or 3 cylinders instead of 4. Not to mention previous to this it would bog down when stopping at intersections like the idle was low. I was able to get it home that day although it stalled at intersections. During the problems my check engine light cam on and so did my oil pressure light. I took it to the garage that my warranty company told me to.
The garage report is written as: "car brought in because engine was missing, we took valve cover off to reveal rockers, and the #4 cylinder intake rocker was loose. We then removed the rocker and the lifter came apart. Body of lifter was stuck in cylinder head, we then had to allthread to lifter body and slide hammer it out. The lifter bore was scarred, we cleaned it up, installed new lifter and reassembled. It runs fine."
they also replaced the plug wires.
my question is: My warranty is up in 2 weeks, and unfortunately I don't know a whole lot about engine repair. But from what I do understand this seems to be a big deal within my engine. Did the garage just put a band-aid on my car. Because I definitely can not afford replacing parts of my engine continuously. Can someone offer a bit of advice? If the lifter bore is scarred could that cause me to lose compression or cause future problems with my engine?