Plain and short.
The Free plan costs nothing, so there is nothing to refund — try everything there first.
Paid plans are billed monthly in advance. If you cancel, you keep the plan until the end of the period you paid for and are not charged again; we do not refund the unused part of a month.
If we charged you by mistake, or the service was unavailable for a material part of a paid month, write to proitz@grandfieldmedia.com within 30 days and we refund that charge to the original payment method within 7 working days.