If an automatic payment for MetaSlider Pro fails, you will be notified by email. You will then have the opportunity to pay for your next subscription period via card or PayPal. This can be done from your account page here on MetaSlider.com.
Please note that a chargeback will automatically count as a cancelled payment.
Also, in terms of purchased support, once your paid period has expired, you are not entitled to any support with issues pertaining to MetaSlider Pro.