Ask the studio directly, through Messages or however you normally reach them. They took the payment and they set the refund policy, so they are the only party who can issue one.
Say what you booked, when, and what went wrong. Most refund conversations are resolved in one message.
Friday Scheduling cannot refund a service on a studio's behalf, because the money never passed through us. What we can do is help you reach a studio that has gone quiet, and correct anything the app is displaying wrongly about your booking or your history.
If you paid by card and believe a charge is genuinely fraudulent rather than disputed, your bank or card issuer is the right route, and they have their own timescales.