Unfortunately, our back-end registrar (TuCows) isn't very flexible and they don't offer any refunds.  Although, to their credit--I don't know of a domain registrars that do offer refunds.   The DomainRocket.com service is essentially just reselling services offered by TuCows and they handles the credit card transactions.   They give us a limited amount of power and a tiny profit (a couple dollars per domain/year).

Beware that if you dispute the credit card charge with your credit card company then TuCows will likely suspend your domains.

You can turn off auto-renew for your domains from within the DomainRocket control panel by clicking on the button shown in the Domain Manager area: