Are they the echo show? I don't get ads on my dots but the show shows ads most of the time, when I really want it to show the clock face instead.

Region might matter. I set it to Australia/New Zealand region and for about a year it didn't show ads. But it does, now, even though it talks with an Australian accent.

The Alexa's with video screen will start to show ads no matter now many times you set it to no ads. There are settings for No Ads, and after a few days, that setting is reset to allow ads. I had one so I could quickly see my Blink camera, but I threw it away because it kept showing ads.