Slide awnings are a poor substitute for a properly sealed slide out. A properly installed slide will not leak.
The problem with slide awnings is they flap in the wind and are noisy, they tear, they pool rain water and so on.
The dealer needs to find the leak and repair it. It could be poor caulking or a damaged slide seal.
As for now, get a wet/dry shop vacuum and suck as much water as you can out of the carpet. They get fans blowing on it to dry it. If your subfloor is particle board, MDF or chip board it haas probably already started to come apart. I'd have the dealer pull back the carpet and check the subfloor.
Ken