Monthly and annual licenses are only available on a recurring payment plan. To cancel after one month or one year, you can simply deactivate the recurring option in your product settings.
Once you have made a successful transaction, sign in to My Chaos, then go to Products, click on Active Products and select the product of your choice.
Next to "Auto renewal:" click on "Disable auto renewal". You will see a pop-up window asking you to confirm. Click on "Disable auto renewal.”
There is no limit on how many times you can do this within a period that has been paid for. If you disable auto renewal and the period you’ve paid for elapses, you cannot re-activate the automatic payment so you will have to make a new transaction.