illustrator plan

All plans auto renew

The annual plan, paid monthly (about $20) is an ANNUAL plan, with a one year commitment (promise to pay $240, in other words). Adobe give a generous 50% discount on the remaining fee for the year if you cancel early.

The monthly plan (about $30) is indeed a commitment of only a month, you can cancel at the end of any month.

If you did buy the more expensive monthly plan, you agreed to pay EVERY MONTH until you cancel

SOME programs are available Monthly https://community.adobe.com/t5/Get-Started/Being-charged-for-a-full-year-when-i-m-on-month-to-month/td-p/10248222 - links and pictures

To Cancel https://helpx.adobe.com/manage-account/using/cancel-creative-cloud-subscription.html

>says that i will be charged again next month

That is correct... you bought a ONE YEAR CONTRACT with monthly payments https://www.adobe.com/legal/subscription-terms.html

On the forums we can't help you with account issues.

Please contact Customer Care. https://helpx.adobe.com/contact.html