Why did I get a notification from my bank that my credit card has been charged $20-$50?
A temporary $20-$50 pre-authorization fee is collected at the initial stage of the charging session, to make sure the account is valid.
Once the charging session completes, only the final charging session fee is collected, and the $20-50 pre-authorization fee is reversed back to the credit card immediately. But depending on bank processing time, it could take up 7 days for the amount to be credited back to the credit card account.