TOS changes:
Due to our contract with a Nigerian prince who is seeking to exfiltrate his family wealth, your last month's bill of $14.99 will be refunded in its entirety, and the fee schedule from now on will be as follows:
[6 pages of legalese]
$39.99
[3 more pages of legalese]
You can opt out at any time by sending a notarized letter to our legal department at ___. Should you wish to continue using our service, we will auto-renew you at the new rate on your next login.
I had exactly this case with T-Mobile in my country. They'd sent me price increase but I didn't see it and realised only when got charged 3x more for internet I didn't use. Then I answered them with email that I resign, but they wrote that they need my signature and I need to send it by post office or go to one of their places