It’s like the old joke: How do you make $1 million dollars? Start with $2 million dollars.
If a bank calls you to report unusual traffic on your account (which many banks will do but they are not required to do), YOU start the conversation by saying what activity is legitimate (i.e., what transactions were made by you and how much and to whom the transaction was made). But YOU are the one responsible for keeping track of your bank account transactions. YOU are the one who has to know that you shopped at Target twice in one day and how much you spent each time. The bank only sees the transaction activity.
Chumba Casino, owned by Virtual Gaming Worlds, has operated in the U.S. since 2017. It has run into legal issues in a few states, like Kentucky, for violating
state gambling laws. These violations were settled in class action suits. Michigan is joining Idaho and Washington state in no longer offering Chumba Casino/VGW products to consumers but Michigan’s decision was not due to complaints about Chumba.
Although I have not seen any issues with overcharges or illegal bank withdrawals by Chumba, you can consult with an attorney in California for a personal review, to see if you have any legal action to pursue. Again, I think you will have difficulty showing this.