If my memory serves me correctly it can take some time for the refund to show, sometimes up to a week. I am not exactly certain on that though.
As far as the refund itself it will go back into your Paypal account, not your bank. It doesn't matter that it was part funded from both as Paypal has no way of refunding it back to your bank. That would be something you would have to do yourself, if you wanted to that is.
If I was you though I would call Paypal to clarify the amount of time it takes for the refund to show. Just to make sure