We see that you have an active subscription of Adobe PDF Pack (Annual Pack). If you are willing to convert it to the monthly subscription, then you may refer to Learn how to change your Adobe Creative Cloud plan and try the similar steps suggested to change the plan for creative cloud membership.
If you see the option to change it to Month-Month then you can simply change it. Else you have to cancel the current plan and resubscribe.
For further assistance you can contact to our billing support team via chat-
1- Refer to the link Contact Customer Care
2- Select Account issues
3- Show me my contact options.
Let us know if it still doesn't work.