The company responded to my request promptly. They send a technician, Alex, to my apartment the next morning! I am really satisfied with there responding speed and Alex's professionalism. He was quick to identify the ants type and applied the most effective treatment, instead of simply offering to spray the apartment. I did research afterwards, apparently for pharaoh ants, if you spray the space, the queen will just move to a new location and infest other area, baiting treatment is the way to go. So kudos to Alex. I got 3 month warranty, I was looking for 6 month warranty but they said 3 month is enough for a one-bedroom apartment (space is limit, if they reappear it shouldn't take long). Anyway, my only star reduction was because of this.
PS. I purchased over the counter stuff from Canadian tire. The terror bait 6 pack, I think that's the name and they didn't work...