Skype doesn't offer a phone support.
How to contact Customer Service: https://support.skype.com/en/faq/FA1170
Perhaps it is not clear for you when recurring payment is taken?
It is always 3 days in advance.You don’t lose these three days: your subscription is still valid for the full period that you sign up for. Skype charges your bank or PayPal account three days in advance to ensure prompt delivery of your subscription.
I hope it helps!