Help! Wedding Catastrophe?

I have no idea what to do. I am getting married September 22 and the wedding coordinator just informed me that he will be unable to be at our wedding because of another wedding being moved up to that date. He knew about this other wedding a month ago and didn’t tell my mother until yesterday (go figure after she paid her second installment for his services.) A few weeks ago I thought it was strange that I was jumping through hoops in order to get things ordered. He made no timeline and obviously didn’t fulfill his contract. Honestly, I wouldn’t mind doing these things but the fact is we paid him to make this stressful time easier. What should I do? Do you think suing is the right answer? I am so lost right now. Please help!