Paid Leads: Customers Schedule Appointments and Then Disappear

I’d like to share an issue I’ve experienced several times with paid leads.
A customer contacts me, we exchange messages, and agree on a specific date and time for me to come out. I reserve that time for the customer. In some cases, the customer later asks to reschedule, I agree and reserve another time — and then the customer completely stops responding.
In these situations, I lose more than the money I paid for the lead. I also lose valuable working time because I kept that appointment available and may have missed the opportunity to accept another job.
I understand that a customer simply not responding to an initial message is part of doing business. But I believe the situation is different when a customer has already communicated with a Pro and confirmed or rescheduled an appointment.
I would like Thumbtack to consider a policy that allows a lead refund or credit when a customer confirms an appointment and then becomes completely unresponsive.
It would also be helpful to have a simple way for Pros to report these cases and provide the Thumbtack message history as evidence.
I have several real examples in my account where this has happened.
Have other Pros experienced the same problem? How do you think Thumbtack could better protect Pros in these situations?