Sounds like petsmart.. apparently pacu only need 30g tanks and only grow to 6''.
I had a hilarious encounter at petsmart in the USA (Im from Canada).. the girl first dropped my fish on the floor, then couldn't figure out how to get it off the floor.. she dragged it along the floor with the net and tried to jam it into a plastic container.. most of its tail was missing after that.. then she just put it back into the container and decided to bag it.. I didn't bother asking for her to catch another fish, as I figured she would probably just mess that up too.. Then she filled the bag with 80% water, and couldn't figure out why she couldn't tie it.. someone else told her to empty some water and get a larger bag.. that took her 10 minutes. Then she decided to stop and talk to another customer for 5 minutes. Right when I asked her if she could help me, she dropped a large rock ornament on 2 gouramis and killed them both.
I'm pretty patient, but even I was losing my patience after 15 minutes of dealing with this girl.
Gotta love the ''special'' fish stores that everyone loves to hate.