If you have any doubt about the activity, you can contact Contributor support: https://helpx.adobe.com/stock/contributor/help/Need-Help-Contact-Us.html
Irregularily high downloads is normally a sign of fraud, but such fraud can only happen with your help. So I suppose that is not the case.
Adobe does not provide protection against resale, but according to the licensing terms, that is forbidden. I do not think that stealing from Adobe stock to resell is a lucrative market. As soon as you got caught, your account gets shut down on any decent platform.
Adobe does not offer exclusive contributor contracts, so if you are exclusivly on Adobe stock, that is your decision.
From time to time, I google my images to see, where the are getting used. And I have no doubt that the use is correctly licensed.
BTW: Adobe offers API access to certain shops, so that they can use the stock database for print on demand wall papers or similar. When a buyer selects your asset, you get accounted one sale. So that is good for you, for Adobe and the shop.