If you signed up for a DealMachine plan through Apple you would have to cancel your subscription from your Apple account otherwise please follow the steps below.
Go to the Account Settings page on the DealMachine website on your computer or Android phone.
Click Plans & Add-ons.
Click Cancel Plan on the lower part of your screen.
Make sure to follow the steps to completely cancel your account.
I hope this helps!
A kind reminder to reach out to our support team should you have questions or need help with anything.