You can't offer trials or even easily make refunds accessible via in-app purchases. What you can do is actually make manual deposits or write checks back to the users who ask for it. But the purchase behavior associated with in-app purchases really shouldn't require any promise of a refund. In fact, doing so might make people *less* likely to purchase being that you're telegraphing a weak offering.

Happy to talk through alternate ways of testing pricing and willingness to pay in a call.