I’m sorry but Fiverrs own terms of service stipulate that refunds will only be returned to Fiverr buyers in the form of credit.
I know exactly how you feel. You feel robbed, stung financially, and like this whole deal stinks. Recently, however, I found a whopping $579 charge on my card for automatic renewal of an online video making site which I don’t use anymore. The thing is, after a big argument with them, I have had to accept that yes, I clicked the automatic renew button when I signed up and yes, them taking a charge is fully within their rights.
My advice would be to try and turn a bad situation into a good one by using your new Fiverr balance to buy a service which you need and actually get something for your money.