Yes, you can cancel at any time by accessing your account.
Select the balance amount that you want to start with, and credits will be deducted from your balance as you use our AI. You can top up at any time, at which level is appropriate to you. There is no difference in cost per credit.
Secure. Transactions are processed by third party vendors. We never receive your credit card information, nor store it anywhere. You can find out more here: https://docs.stripe.com/security