Which account the refund will go into
When a refund is processed it will go to the same account that made the original payment. It is not possible to specify a destination account for a refund.
If the original card has been replaced by the same bank since the original payment, the bank should automatically forward the refund to the new card.
When should I see it
It may take a few days for the refund to reach your bank account. Following is copied from Stripe website (Stripe is a company similar to Paypal, we process payment and refund through them):
We’ll submit any refund you make to your customer’s bank immediately. However, it may take anywhere up to ten business days for your customer's bank to process the refund and for the funds to be returned to the account.
More information could be found on the Stripe refund processing time page.
In some cases, the refund might be processed as a reversal, meaning the original payment will disappear from the account statement entirely and the balance will reflect as though the charge never occurred.