Air's refund policy is described in their Terms and Conditions under section 8.2:

8.2 Subscription Fees. [...] If you cancel your subscription, you may use your subscription until the end of your then-current subscription term; your subscription will not be renewed after your then-current term expires. However, you will not be eligible for a prorated refund of any portion of the subscription fee paid for the then-current subscription period. [...]

Read Air's full terms and conditions document.