I have been having trouble with my ac blowing hot air at low speeds, and found my fans on the front grille are blowing air outwards instead of into the engine compartment. Im hoping its an easy fix, but any information on fixing this sort of issue would be greatly appreciated.
As various comments state, you have either had the fan replaced back to front (which I don't think can happen in a Prius, looking at the layout) or the wires were attached with the wrong polarity.
If you can take it back to the shop that did the work, they should sort that out for free as it was a mistake, but if you want to do it yourself it's very straightforward. No soldering required - these use spade terminals and crimp connectors so either look for the connector block and swap the connectors over (they are easy to remove) or change the wires over at the fan end.
This video shows useful detail