In California, you're not allowed to bring an attorney to a SCC -- only to Superior Court -- so, obviously, there's no attorney fees when attorneys are not allowed.
Some other states do allow attorneys in SCC, however.
They send a representative, probably someone from their legal department if they have one. The important thing is that both you and the company are arguing on much more level footing. You don't need to be thoroughly versed in court procedure, and the whole process is generally a little more lax than in superior court.
With that said, the company can still pump tons of money into things behind the scenes, but because the stakes are so low, and not necessarily precedent-forming, they're not likely to actually invest that much money into fighting you. And even if they do and you lose, since you brought the lawsuit and there are no attorney fees, the most you'd end up spending is the court fees (potentially the company's court fees, but those are minimal too.)
To level the playing field. The idea of Small Claims Court is to have a cheap way to resolve monetary disputes, without having to rely on complex procedures and expensive lawyers. So, since you as an individual wouldn't have a lawyer when you sue someone for $300, it wouldn't quite be fair if the company was afforded one.
Keep in mind that anything you take to a Small Claims Court you can also take to to a Superior Court, where only lawyers are allowed, unless you're an individual, and are representing yourself.
Not every state bans lawyers from SCC. But in California, you'd only face a lawyer in SCC if you sue them for not returning your money, or they sue you for not paying them their fees.