This depends on the organizers of the examination you want to take part in. But in general, there are no such refund policies for most of the examination. If you are paying for the examination then you are intended to give the examination thats why you are paying, right?. So if the examination you are sitting for have the rules you get the money refund, but in most cases this will not be the case.

I hope this answer helps. All the very best for your future endeavors!