Billing Issue

Hi.  My annual subscription plan ended on Aug. 20, 2023 and I cancelled the plan before the plan was over.  But I now have an outstanding charge of $24.90 that was charged on Aug. 21, 2023.  I received an email confirming that I cancelled my plan on Aug. 22, 2022 so I don't understand why I'm being charged this amount.  Also, is this amount for an annual plan or a monthly plan?  Can someone from the billing team advise?  I tried to contact by phone many times already but there seems to be no answer.  I look forward to your reply.  Thank you.

Regards,

CK