Amount reserved in customer's bank account

If a transaction is cancelled, or interrupted, the money might still be reserved in your customer's account for a few days. 

A reservation does not mean that the money will be charged to the account. The bank reserved the money at the time of the purchase and it was done to make sure there were sufficient funds to complete the payment. 
 
The reservation will be removed after a few business days and the money will then appear in the account again.