I had an appointment this morning for a dog sitter. The sitter was not home and I am having to take the dog off work as i drop my dog on the way to work. I will never use this sitter again, how to i get a refund?

I had an appointment this morning for a dog sitter. The sitter was not home and I am having to take the dog off work as i drop my dog on the way to work. I will never use this sitter again, how to i get a refund?