I know many providers have started to want deposits just to confirm an hour appointment. Many of us have resisted this, and one of the main reasons is this that happened with a well known provider. It is a Thread about Winter Kay, and how all of a sudden things changed around the end of September and first part of October. Long thread in the KC Men's Lounge about the issue. It is also on other review sites, and she is no longer on P411.
https://www.eccie.net/showthread.php?t=2814019
While I never lost a deposit, I did have an appointment set up the day before with a provider that was touring, and when I went to confirm the day of she was out of town already. If the provider decides she doesn't want to come back to the area, she has little incentive to refund a deposit.