problem with nano credit

[Quitit]

I was registering for a Premium account and my nano credits were taken off for 2 months of subsciptions, but I only wanted one for now. It was an accident. I was confused by the button on the lead in page and then there was another. I needed those credit for more fields and was wondering if you could please take off one subcription for premium and allow me to have those credits back or simply allow one months worth of credits to go towards the purchase of more planet fields.
Thanks
David