Welcome to the world of renting anything. We eat $1000s of dollars of damages each year because it just isn't worth the time, effort and mental energy to chase money you are never going to get. Damages on credit card deposits are going to be disputed, and you will likely not win. Good luck trying to get large cash deposits and good luck keeping someone's cash when they come calling for a refund of their deposit.
When renting, loses due to damage, misuse, carelessness, negligence and everything else is a cost of doing business. The fact you couldn't turn around the rental in time to rent again is not generally recoverable. That's why rental companies have many units, not one or two. They anticipate and plan for down time because it will be a fact of rental business life.
Finally, I don't think this problem is limited to the company you deal with. That industry is sketchy to begin with and I would assume all the companies over-promise and under-deliver in their marketing to potential owners. That is why whenever a thread about renting rigs is started, it is quickly filled with the advice of "not in a million years".
