If I were you, based on all the reviews here on this site I would simply shut down my account with them completely! And, as someone suggested, contact Paypal and have them block the merchant from further charges!

Then, move on to another music service with a better reputation, like SoundCloud! You can also do a Google search on "list of websites like SoundCloud!
I know they will treat you right!

In the end, if the folks who run this website don't honor the artists who perform on it then just don't honer them with your money!

Stay clear!

Hopefully you used Paypal as a buffer to your credit card access.
Go to PayPal and cancel the automatic billing. ReverbNation will then suspend your account because they don't tolerate people protecting themselves financially, but you'll be better off. If you gave them your credit card number, call your bank or go to your online statement and contest or block their transactions. Best of Luck. We've all been through this.

Nothing comes easy! No one will launch your career aunless you!