Most events will NOT refund your money. For any reason! Just accept this fact and move on.
Many of us are used to being able to get some or all of our money back when we decide not participate in something for a good reason. However, this is not true of the fitness event world. There are just too many people who get injured, have conflicts arise or for whatever reason cannot fill the void of the entry they committed to when they hit the "submit" button to register for an event on its website.
Generally speaking, your only options are to "grin, bear it and move on" or find a replacement athlete through which you can provide your entry. Many events allow this practice, but it's probably good to double check with race organizers.