Do I deserve a refund since he told me that he will?

I got a moving violation ticket on my way to another city in April 2017. I sent a letter to the judge to request a hearing but seems like the letter was never received. After few weeks, I received a collection mail requesting the fine to be paid with interest then I hired a lawyer dispute the case. I explained the situation of my case and the lawyer told me that he can fight the case if I pay him his fee but he will refund my money if he is not successful. After about a month, I received another letter from the same collection and found out that my driver’s license was suspended. I paid the collection fee and reinserted my license. I call the lawyer to refund my money but his assistant told me that they don't guarantee to win cases and they can't refund. I am still waiting to talk to the lawyer.