WAIT! Are you canceling because you're still getting ads?
If you're dealing with ads that show up while you're doing completely unrelated things, like texting or writing an email on your phone, or doing work on your desktop, then more than likely you have malware or adware. It's also possible that a generally legitimate app you have is behaving badly because its developers want to earn a few extra bucks.
Unfortunately, all ad blockers, including ourselves, have a hard time blocking these types of ads because the nefarious apps in question will take specific steps to make sure the ads get shown. Some will include all the ad materials in their installation so that they don't need to make any DNS queries at all. Others may bypass your device's DNS settings and have their own hard-coded servers that they query. The only surefire way to get rid of these types of ads is to get rid of the app that's behind them. The good thing is that we're willing to help! Shoot us an email at email@example.com, and include a screenshot of the ads if you can. We'll investigate right away and work with you to clean up your device.