Did a cheap brake job at a roadside garage, did I get ripped off?

Two weeks ago I got my Kia Cerato’s front pads changed at a small garage on my way home, and now I keep wondering if I made a mistake. The price was very low, about half of what the dealer told me, and the job took only forty minutes. The mechanic was friendly, but he did not show me the old pads, and the receipt just says brake job with a total price. The car stops fine so far, and the squeal is gone. But I have been reading since then, and I found some talk about Quality Brake Pad Replacement Dubai, and it made me realise a proper job has more steps than I thought, like checking the discs and cleaning and greasing the brake parts. I do not remember him doing any of that. I live in Dubai and drive about thirty minutes to work each day in heavy traffic, so my brakes get a lot of use. The car has about fifty five thousand kilometres. Now I have a few questions. How can I check if the pads are really new, by looking through the wheel? Is a low price a warning sign, or do small garages just have lower costs? Should I go back and ask him what brand of pads he used? Also, how long should I wait before I worry if I hear a new noise or feel a shake when I brake? Is it okay to ask another shop to take a quick look, even if they did not do the job? If you got a cheap brake job, please tell me how it turned out, what you paid, and what you would do differently. Easy answers help me most.