Renew process with Teamviewer

I have used Teamviewer successfully until I received my invoice to renew in June this year. The price was very expensive and I was not able to afford or justify the amount. There was no instructions on cancelling. I thought if I didn't pay, my subscription would not be renewed. They tried to run my credit card which was declined. I then tried sending them a message to cancel via a " create a ticket " function on their website. They do not respond to those " tickets" and there is no other way to contact them. The Teamviewer support is now continually mailing me to pay. I have found an alternate method of remote access for 1/5th of the price. The entire Teamviewer experience is extremely user unfriendly