Refunding expensive leads

Can someone please help me? We are a small business, just starting last year. We got a direct lead from thumbtack this week and the lead was $180. It was fine when I realized the amount of guests, but not when I realized she had only wanted a few options, not catering for her entire service. Thumbtack estimated the lead cost based on how many people she input, but that wasn’t what she was looking for from us. Even if she had booked with us for extra options, her tab wouldn’t have come out over $1000, and I don’t realistically, or fairly see how this lead would be worth 20% of the party’s revenue. On top of this, we immediately responded, and the customer never replied to initial email, follow up email, or phone calls. I would like to keep using thumbtack as I do feel we get some decent business here, but help us out lol please.