Why does my studio keep asking for debit permissions from me?

The studio has a feature that allows you to charge others to use it.  By default, this feature is turned off when you first rez your studio.  If you enabled this feature you can disable it.  If you did not enable this feature, please be sure you do not have anyone who is able to modify your objects.

The studio does not take money from you for no reason, but is scripted like most vendors to refund the buyer

Solution

You will need to disable the payment feature