Unable to pay

you can cancel your subscription (with a penalty if you're outside the trial period), but you won't be able to continue to use the subscription programs.

check https://helpx.adobe.com/manage-account/using/cancel-subscription.html
p.s. if you're cancelling an annual plan early, there's a penalty (=1/2 the cost of the remaining months).

if the above link doesn't help you cancel, using a browser that allows popups and cookies, contact adobe support by clicking here, https://helpx.adobe.com/contact.html

click contact us (= cryptic icon in the lower right)
in the chat field, type AGENT
be patient, it can take quite a while to reach a human