I believe that Paypal is participating in deceptive and fraudulent practices.

If you pay by credit card and you decide to make a return, the money is returned and credited to the credit card.

If you pay by bank funds and you decide to make a return, Paypal holds the money in your non-interest baring Paypal account instead of crediting the money back to where it originated from. The user is required to "withdraw them" from the Paypal account and deposit them in the bank account. Paypal takes 3-4 business days (and in some cases 5 or more!) to credit the funds back to the bank account.

Paypal should amend it's practice to place ALL credited funds back to the original source and not hold the funds hostage so they can make money on them.