Thank you for this survival advice.
The only “warning” you get before being charged after the first month is an email at 3AM about 10 minutes before the charge goes through.
I suspect this is actually an illegal practice - having to ‘opt out’ of signing up to pay for something.
Happened to me too. Only ‘notification’ that I would be charged was a 3AM email about 10 minutes before the charge… Gee. I didn’t see it in time…
I too was duped by this fraudulent practice, however I cannot find anywhere online to cancel the subscription. My account dhows no subscriptions and no recent orders even though I have an email with an order number and PayPal keeps getting charged. I canceled the auto payment on PayPal to prevent future ripoffs. Even customer service says I have no subscriptions, yet billing keeps happening.
Welcome to the Wyze User Community Forum @dtirecyclers! 
How did you first order the cam that came with the trial subscription?
If ordered thru the Wyze Store on their Website, subscriptions will be found in your account at services.wyze.com.
If you ordered elsewhere, including thru the Wyze App, the purchase and the subscription was most likely processed thru the Apple\iPhone App Store. Unfortunately, Wyze has no ability to manage or change subscriptions obtained thru the OS App Stores.
If it is an Apple\iPhone App Store subscription, it must be cancelled thru the App Store. Another user previously posted a contact phone number for them: 512-884-5022
If it is a Wyze direct subscription, it can be handled by Customer Support
Wyze is deceptive and fraudulent.
Perhaps it isn’t in your best interest to continue to do business with them going forward.
The best of luck to you in resolving your issue.