I have already paid and subscribed for the yearly plan but nextdns is asking every single day to pay again.

I have already paid and subscribed for the yearly plan and the money has also been debited from my credit card. But nextdns is every single day asking me to pay again and change payment method. Either refund what was debited then I will change my payment method or get this error fixed and stop sending email about paying for yearly plan. It's getting tiresome and I am frustrated with the absence of a proper customer support here. I never knew that subscribing to anything can cause this much headache. Please anyone assist.