Return-refund policy in nutshell: This entertainment/educational business works like the cinema/movies.
The customer buys the ticket in advance, online/or at the venue and no matter if she/he comes to attend the show, or stays away, no matter if it was raining or she/he had a bad day, no refund at all, just like when you buy a movie ticket.
In case you did not like the show you are free to tell it to your friends on any platform, but no money back/no refund.